JP4632822B2 - Hermetic compressor - Google Patents

Description

  The present invention relates to a hermetic compressor used for refrigeration, air conditioning, and the like, and more particularly to a technique for improving COP of a hermetic compressor.

2. Description of the Related Art Conventionally, a hermetic rotary compressor in which an electric element and a rotary compression element that is driven by the electric element and compresses a refrigerant is housed in an airtight container is known. In this type of hermetic rotary compressor, generally, a roller that rotates eccentrically is installed in a cylinder with a predetermined clearance to form a crescent-shaped space (so-called compression chamber) in the cylinder, and the roller slides on the roller. A vane that is in contact is provided, and the crescent-shaped space in the cylinder is configured to be pressure-divided by the vane into a low-pressure chamber side that sucks in the refrigerant and a high-pressure chamber side that compresses the refrigerant (for example, Patent Document 1).
JP-A-6-323276

However, in the conventional technology, the sealing performance of the crescent-shaped space in the cylinder is not sufficiently improved, and the cooling efficiency (COP: Coefficient Of Performance: refrigeration capacity / input power) of the hermetic rotary compressor is not achieved. ).
The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a hermetic compressor that can improve the sealing performance between a roller and a cylinder and thereby increase the cooling efficiency. And

In order to achieve the above object, the present invention provides a hermetic compressor in which an electric element and a rotary compression element driven by a rotating shaft of the electric element are housed in a hermetic container. Between the cylinder and the roller constituting the rotary compression element, and the oil supply device for supplying the oil supplied to the peripheral surface of the rotary shaft along with the rotation of the rotary shaft, and the oil supplied to the peripheral surface of the rotary shaft An oil passage that guides the oil supplied to the peripheral surface of the rotary shaft to the upper surface or the lower surface of the cylinder, and the cylinder in the vertical direction. A vertical hole that communicates with the auxiliary oil passage, and an injection port that opens on the inner surface of the cylinder so as to communicate with the vertical hole. And a clearance between the fitting and the front Clearance by characterized in that the adjustable amount of oil injected into the compression chamber.

  Further, the present invention is characterized in that, in the above invention, the clearance is determined in accordance with an excluded volume of the compression chamber.

  According to the present invention, the oil passage for guiding the oil in the hermetic container during the suction process is provided in the compression chamber between the cylinder and the roller constituting the rotary compression element. A sufficient oil film is formed to improve the sealing performance. As a result, the refrigerant is prevented from leaking to the low pressure side during the compression process in the compression chamber, so that the compression efficiency is enhanced, and thus the cooling efficiency is enhanced.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing an aspect of a hermetic rotary compressor 100 according to the present embodiment, and FIG. 2 is an enlarged longitudinal sectional view showing a rotary compression element. The hermetic rotary compressor 100 is connected to a pipe between a refrigerant condenser and an evaporator to form a refrigerator unit. As shown in FIG. An electric element 2 is housed on the upper side of the container 1, and a rotary compression element 4 that is driven by a crankshaft 3 (rotary shaft) of the electric element 2 to compress the refrigerant is housed on the lower side.

  The hermetic container 1 includes a cylindrical shell portion 10 and an end cap 11 fixed to the shell portion 10 by arc welding or the like. The end cap 11 is a relay terminal for supplying electric power to the electric element 2. And a discharge pipe 13 for discharging the compressed refrigerant to the outside of the machine. A suction pipe 6 that guides the refrigerant from the accumulator 5 to the rotary compression element 4 is fixed by welding or the like near the bottom of the shell portion 10.

  The electric element 2 is composed of a direct current motor such as a so-called DC brushless motor, and includes a rotor (rotor) 31 and a stator (stator) 32 fixed to the shell portion 10. 3 is fixed, and the rotational force of the rotor 31 is transmitted to the rotary compression element 4. The crankshaft 3 is rotatably supported by a main bearing 7A (support member) and a sub bearing 7B.

  As shown in FIGS. 1 and 2, the rotary compression element 4 includes a cylinder 41 having a cylindrical shape. The cylinder 41 is connected to a main bearing by a bolt or the like (not shown) between the main bearing 7A and the auxiliary bearing 7B. The main bearing 7A is fixed to the inner surface of the sealed container 1 by welding, and the cylinder 41 is supported by the main bearing 7A. Further, the upper opening of the cylinder 41 is closed by the main bearing 7 </ b> A and the lower opening is closed by the auxiliary bearing 7 </ b> B, and a compression chamber 43 is formed in the cylinder 41.

  In the compression chamber 43, a roller 45 that is fitted into an eccentric portion 44 that is integrally formed with the crankshaft 3 and rotates eccentrically is provided. As shown in FIG. 3, the cylinder 41 is provided with a vane groove 47 between the refrigerant suction port 48 and the discharge port 40, and the vane 46 is slidably disposed in the vane groove 47. ing. The vane 46 is always pressed in the direction of the roller 45 by a biasing member such as a spring (not shown), and reciprocates in the vane groove 47 while sliding on the outer peripheral surface of the roller 45 in accordance with the rotation of the eccentric portion 44 and the roller 45. The inside of the compression chamber 43 serves to partition the pressure chamber side into the low pressure chamber side 43A and the high pressure chamber side 43B.

  Specifically, the roller 45 is provided such that one end of the outer surface thereof is always in contact with the inner surface 49 of the cylinder 41 with a predetermined clearance, and the compression chamber 43 that is a space between the cylinder 41 and the roller 45 has a crescent shape. Formed. The vane 46 comes into contact with the outer surface of the roller 45, and the crescent-shaped compression chamber 43 is partitioned by the vane 46 into a low pressure chamber side 43A and a high pressure chamber side 43B.

A suction pipe 6 (see FIG. 1) is inserted into the suction port 48 of the cylinder 41, and a discharge valve (not shown) is provided in the discharge port 40, so that the refrigerant is discharged by the discharge valve. When the pressure is reached, it is discharged from the discharge port 40 into the sealed container 1.
Therefore, in the hermetic rotary compressor 100, the electric element 2 is supplied from the outside through the accumulator 5 by rotating the roller 45 eccentrically in the compression chamber 43 by driving the crankshaft 3 to rotate. The refrigerant is sucked into the low-pressure chamber side 43A of the compression chamber 43 through the suction pipe 6, compressed while moving the refrigerant to the high-pressure chamber side 43B, and discharged from the discharge port 40 into the sealed container 1, and the discharge pipe 13 Will be discharged out of the machine.

  As shown in FIGS. 1 and 2, oil 8 is stored at the bottom of the sealed container 1 up to the lower surface of the main bearing 7A (indicated by the line AA ′ in the figure). An oil pickup 50 (oil supply device) for supplying oil to the main bearing 7A, the sub-bearing 7B, the rubbing portion between the rotary compression element 4 and the crankshaft 3 and the sliding portion of the rotary compression element 4 is a lower end portion of the crankshaft 3. 3A is provided.

  Specifically, the crankshaft 3 is formed in a cylindrical shape, and a cylindrical oil pickup 50 is press-fitted and attached to the lower end portion 3A thereof. As shown in FIG. 2, a paddle 51 constituting a spiral oil flow path is integrally formed inside the oil pickup 50, and the oil pickup 50 is separated from the lower end 50A by a centrifugal force generated by the rotation of the crack shaft 3. The oil 8 stored in the airtight container 1 is sucked, and the paddle 51 feeds the oil 8 upward. Then, the oil 8 passes through an oil supply hole 52 formed in the oil pickup 50, and the peripheral surface of the crankshaft 3, in particular, the main bearing 7 </ b> A, the sub-bearing 7 </ b> B, and each sliding portion between the rotary compression element 4 and the crankshaft 3. To be supplied.

Here, as described above, since the roller 45 is installed so as to be always in contact with the inner surface 49 of the cylinder 41 with a predetermined clearance, the sealing performance of the compression chamber 43 is not sufficient and the cooling efficiency is lowered. Will be invited.
Therefore, in the present embodiment, there is an oil passage 62 that guides the oil 8 stored in the sealed container 1 to the compression chamber 43 during the refrigerant suction process, and injects the oil 8 into the compression chamber 43. Is provided in the hermetic rotary compressor 100, and a sufficient oil film is formed between the roller 45 and the cylinder 41 by the injected oil 8 so as to improve the sealing performance. Hereinafter, this configuration will be described in detail.

  As shown in FIG. 2, the oil injection part 60 includes an oil storage part 61 provided in the main bearing 7 </ b> A and an oil passage 62 that communicates from the oil storage part 61 to the compression chamber 43 of the cylinder 41. Has been. The oil reservoir 61 is formed by providing the main bearing 7A with an annular space along the outer peripheral surface of the crankshaft 3, and the oil 8 supplied from the oil pickup 50 and guided to the outer peripheral surface of the crankshaft 3 is It is stored in the oil storage unit 61.

  The oil passage 62 includes a sub oil passage 63 formed in the main bearing 7 </ b> A and a main oil passage 64 formed in the cylinder 41 and communicating with the sub oil passage 63. More specifically, the auxiliary oil passage 63 is formed in a first oil passage 65 penetrating from the outer peripheral surface of the main bearing 7A to the oil storage portion 61 and from the lower surface of the main bearing 7A upward (thickness direction). The second oil passage 66 communicates with the oil passage 65. At this time, when the main bearing 7A is fixed to the sealed container 1 by tack welding from the outside of the sealed container 1, the portion P corresponding to the opening end 65A on the outer peripheral surface side of the main bearing 7A of the first oil passage 65 is tacked. By welding, the opening end 65A is closed without using a separate member for closing, thereby reducing the cost and simplifying the assembly work process. If the cylinder 41 is fixed to the closed container 1 instead of the main bearing 7A, the opening end 65A of the first oil passage 65 may be closed using a plug or the like.

  The main oil passage 64 is formed in a vertical hole 67 penetrating the cylinder 41 in a vertical direction (thickness direction) in a cylindrical shape having a diameter of about 4 to 5 mm, and an inner surface 49 of the cylinder 47 so as to communicate with the vertical hole 67. And an inlet 68 that is open. A cylindrical fitting body 69 having a diameter smaller than the diameter of the vertical hole 67 is loosely fitted in the vertical hole 67, and as shown in FIG. 4, the peripheral surface 67 </ b> A of the vertical hole 67 and the fitting body 69. A predetermined clearance 70 is formed between the outer peripheral surface 69A.

  Further, during the step of sucking the refrigerant into the compression chamber 43, the injection port 68 opens to the cylinder inner surface 49 on the low pressure chamber side 43A in order to inject the oil 8 stored in the oil storage section 61 into the compression chamber 43. In particular, as shown in FIG. 3, the injection port 68 has a predetermined angle θ1 to θ2 (θ1: 0 °, θ1 to θ2) with reference to a reference line L connecting the suction port 48 and the center point O of the cylinder 41. (θ2: 170 °, more preferably θ1: 125 °, θ2: 165 °) (opening in the illustrated example is approximately 125 °).

Since the refrigerant discharge pressure (for example, 3 MPa) acts on the oil 8 in the sealed container 1 under the above configuration, the high-pressure oil 8 stored in the oil storage unit 61 is reduced in the low pressure in the compression chamber 43. The pressure is injected into the low pressure chamber side 43A of the compression chamber 43 of the cylinder 41 via the oil passage 62 composed of the auxiliary oil passage 63 and the main oil passage 64 due to the differential pressure with the internal pressure (eg, 1.1 MPa) on the chamber side 43A. The
Therefore, the oil 8 is injected into the compression chamber 43 during the refrigerant suction process, and a sufficient oil film is formed between the cylinder inner surface 49 and the roller 45 by the oil 8 to improve the sealing performance. As a result, the low pressure chamber side 43A and the high pressure chamber side 43B are more reliably separated in the compression chamber 43 of the cylinder 41, so that the refrigerant sucked into the low pressure chamber side 43A is compressed into the high pressure chamber side 43B (compression In the step), leakage of the compressed refrigerant to the low-pressure chamber side 43A is prevented, and the compression efficiency of the refrigerant is increased, so that the cooling efficiency of the hermetic rotary compressor 100 is improved.

  In the present embodiment, the amount of oil injected into the compression chamber 43 is adjusted by adjusting the clearance 70 between the vertical hole 67 and the fitting body 69. The ratio R to the displacement volume V of the compression chamber 43 is determined so as to be within a predetermined range. More specifically, when the ratio R is too small, the clearance 70 becomes too narrow and the oil 8 is not injected into the compression chamber 43. On the contrary, when the ratio R is too large, The oil 8 is excessively injected into the compression chamber 43 and liquid compression occurs. Therefore, in the present embodiment, when the displacement volume V of the compression chamber 43 is about 5 to 5.5 cc, the clearance 70 is set to about 10 μm to 30 μm, thereby preventing liquid compression due to excessive injection of the oil 8. However, the sealing performance between the cylinder inner surface 49 and the roller 45 is enhanced.

  As described above, according to the present embodiment, the compression chamber 43 between the cylinder 41 and the roller 45 is provided with the oil passage 62 that guides the oil 8 in the sealed container 1 during the suction process. A sufficient oil film is formed between the cylinder 41 and the roller 45 by the oil 8 injected into the chamber 43, and the sealing performance is improved. Therefore, the refrigerant is prevented from leaking to the low pressure chamber side 43A during the compression process in the compression chamber 43, so that the compression efficiency is increased, and thus the cooling efficiency of the hermetic compressor 100 can be increased.

  In particular, in the present embodiment, the oil passage 62 is opened on the inner side surface 49 of the cylinder 41 so as to communicate with the vertical hole 67 passing through the cylinder 41 in the vertical direction and communicating with the auxiliary oil passage 63. Oil that is configured to have an inlet 68 and that is loosely fitted into the vertical hole 67 to provide a clearance between the vertical hole 67 and the fitted body 69, and is injected into the compression chamber 43 by this clearance. Since the amount can be adjusted, the oil amount can be easily adjusted only by changing the size of the fitting 69.

  Further, according to the present embodiment, the clearance is provided by loosely fitting the fitting body 69 in the vertical hole 67 constituting the oil passage 62, and this clearance is adjusted according to the excluded volume V of the compression chamber 43. Liquid compression due to excessive injection of the oil 8 can be prevented, and only the amount of oil that can improve the sealing performance between the cylinder inner surface 49 and the roller 45 </ b> A can be injected into the compression chamber 43.

  Note that the above-described embodiment is merely an aspect of the present invention, and can be arbitrarily modified within the scope of the present invention. For example, in the above-described embodiment, the hermetic rotary compressor 100 including one cylinder 41 is illustrated. However, the present invention is not limited thereto, and the present invention is also applied to the hermetic rotary compressor 100 having two cylinders. Of course it is possible.

It is a longitudinal section showing one mode of a hermetic rotary compressor concerning an embodiment of the invention. It is a longitudinal cross-sectional view which expands and shows a rotation compression element. It is a top view of a cylinder. It is a longitudinal cross-sectional view which expands and shows a clearance.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Airtight container 2 Electric element 4 Rotary compression element 7A Main bearing 7B Sub bearing 8 Oil 41 Cylinder 43 Compression chamber 43A Low pressure chamber side 43B High pressure chamber side 45 Roller 46 Vane 48 Suction port 50 Oil pickup (oil supply device)
60 Oil injection part 61 Oil storage part 62 Oil passage 67 Vertical hole 68 Inlet 70 Clearance 100 Hermetic rotary compressor

Claims (2)

In a hermetic compressor in which an electric element and a rotary compression element driven by a rotating shaft of the electric element are accommodated in a sealed container,
An oil supply device that supplies oil stored in the hermetic container to a peripheral surface of the rotary shaft as the rotary shaft rotates;
An oil path that guides oil supplied to the peripheral surface of the rotary shaft to a compression chamber between a cylinder and a roller that constitute the rotary compression element during a suction process ;
The oil passage includes a secondary oil passage that guides oil supplied to a peripheral surface of the rotating shaft to an upper surface or a lower surface of the cylinder, a vertical hole that passes through the cylinder in a vertical direction and communicates with the secondary oil passage, An inlet opening in the inner surface of the cylinder so as to communicate with the vertical hole,
A sealed type characterized in that a fitting body is loosely fitted in the vertical hole, a clearance is provided between the vertical hole and the fitting body, and the amount of oil injected into the compression chamber can be adjusted by the clearance. Compressor. The hermetic compressor according to claim 1 , wherein the clearance is determined according to an excluded volume of the compression chamber.

Images