TWI701384B - Compressor that can inhibit the discharge of refrigerating oil - Google Patents

Abstract

The present invention suppresses the discharge of refrigerating machine oil from the compressor accompanying the discharge of refrigerant. The compressor 5 includes a housing 10, a motor 20, and a compression mechanism 40. The housing 10 includes a cylindrical portion 11 having an inner diameter of the first dimension D1. The motor 20 includes a rotor 22 having an outer diameter of a second dimension D2. The compression mechanism 40 generates high-pressure refrigerant by compressing low-pressure refrigerant. The ratio D1/D2 of the first dimension D1 to the second dimension D2 is 1.8 or less.

Description

Compressor that can inhibit the discharge of refrigerating oil

The present invention relates to a compressor capable of suppressing the discharge of refrigerating machine oil.

Compressors are installed in refrigeration devices such as air conditioners and refrigerators. The motor of the compressor mounted in Patent Document 1 (Japanese Patent Laid-Open No. 2006-144731) rotates at a relatively slow rotation speed of 15 to 75 rps (rotation per second). If, on the contrary, the motor of the compressor rotates at a high speed, the output capacity that contributes to the compression of the refrigerant can be increased. Therefore, in the case of high-speed rotation, the output capacity required by the refrigeration device can be realized by a smaller compressor, and as a result, cost reduction can be achieved. [Prior Art Document] [Patent Document] [Patent Document 1] Japanese Patent Laid-Open No. 2006-144731

[Problem to be solved by the invention] When the motor of the compressor is rotated at a high speed, various dynamic forces are applied to the refrigerating machine oil stored in the compressor shell or the refrigerating machine oil attached to the sliding part of the compression mechanism . At this time, it promotes the mixing of refrigerating machine oil and refrigerant. As a result, a phenomenon called "oil loss" in which refrigerating machine oil is discharged from the compressor together with the high-pressure refrigerant is likely to occur. The subject of the present invention is to suppress the discharge of refrigerating machine oil from the compressor. [Technical Means for Solving the Problem] The compressor of the first aspect of the present invention includes a housing, a motor, and a compression mechanism. The housing includes a cylindrical portion with an inner diameter of the first dimension. The motor includes a rotor with an outer diameter of the second dimension. The compression mechanism generates high-pressure refrigerant by compressing low-pressure refrigerant. The ratio of the first size to the second size is 1.8 or less. According to this structure, since the outer diameter of the rotor is large, the high-pressure refrigerant moves a long distance along the surface of the rotor. During this movement, the oil droplets of the refrigerating machine oil mixed with the high-pressure refrigerant can get an opportunity to escape from the high-pressure refrigerant. Therefore, the discharge of refrigerating machine oil from the compressor can be suppressed. The compressor of the second aspect of the present invention, in the compressor of the first aspect, further includes a refrigerating machine oil having a viscosity of 53 mm ² /s or less at a temperature of 40°C. The refrigerating machine oil is configured to lubricate the sliding parts of the compression mechanism. According to this structure, the viscosity of refrigerating machine oil is relatively low. Therefore, the sliding loss of the compression mechanism can be reduced, and the high-speed rotation of the rotor becomes easy. In the compressor of the third aspect of the present invention, in the compressor of the first aspect or the second aspect, the rotor is configured to rotate at a rotation speed of 75 rps or more. According to this structure, the rotor rotates at high speed. Therefore, the output capacity of the compressor increases. The compressor according to the fourth aspect of the present invention further includes a crankshaft in any one of the first to third aspects. The crankshaft transmits power from the rotor to the compression mechanism. The compression mechanism sprays high-pressure refrigerant along the crankshaft toward the rotor. According to this structure, the high-pressure refrigerant discharged from the compression mechanism first travels along the crankshaft. Therefore, the high-pressure refrigerant can stably reach the surface of the rotor. In the compressor of the fifth aspect of the present invention, in any one of the first to fourth aspects, the compression mechanism is provided below the motor. According to this structure, the compression mechanism is provided below the housing. Therefore, it is easy to use the refrigerating machine oil stored under the casing to lubricate the sliding parts of the compression mechanism. The compressor according to the sixth aspect of the present invention is further provided with a discharge pipe in any one of the first to fifth aspects. The ejection pipe ejects the high-pressure refrigerant to the outside of the housing. The ejection pipe is arranged above the motor. The motor further includes a stator. The gap between the stator and the rotor functions as a passage for high-pressure refrigerant to pass through. According to this structure, the discharge pipe and the compression mechanism are located on opposite sides of each other on the basis of the motor. Therefore, when the high-pressure refrigerant moves along the path from the compression mechanism to the ejection pipe, the motor functions as an obstacle. When the high-pressure refrigerant avoids the obstacle, the oil droplets of the refrigerating machine oil mixed with the high-pressure refrigerant have a chance to escape from the high-pressure refrigerant. Therefore, the discharge of refrigerating machine oil from the compressor is further suppressed. In the compressor according to the seventh aspect of the present invention, in any one of the first to sixth aspects, the compression mechanism has a discharge hole for discharging a high-pressure refrigerant. The third dimension, which is twice the distance between the rotation axis of the rotor and the ejection hole in plan view, is smaller than the second dimension. According to this structure, the high-pressure refrigerant moves from the discharge hole of the compression mechanism to the outer edge of the rotor. During this movement, the oil droplets of the refrigerating machine oil mixed with the high-pressure refrigerant have a chance to escape from the high-pressure refrigerant. Therefore, the discharge of refrigerating machine oil from the compressor is further suppressed. In the compressor of the eighth aspect of the present invention, in the compressor of the seventh aspect, the ratio of the third dimension to the second dimension is 0.5 or less. According to this configuration, the high-pressure refrigerant moves along the surface of the rotor by a distance of at least 50% of the radius of the rotor. Therefore, the discharge of refrigerating machine oil from the compressor can be suppressed more reliably. In the compressor according to the ninth aspect of the present invention, in any one of the first to the eighth aspects, a recessed portion for temporarily accommodating the high-pressure refrigerant discharged from the compression mechanism is formed on the surface of the rotor facing the compression mechanism. According to this structure, the high-pressure refrigerant is temporarily accommodated in the recess before reaching the gap between the stator and the rotor. Therefore, the moving distance and moving time of the high-pressure refrigerant increase, thereby further suppressing the discharge of refrigerating machine oil from the compressor. In the compressor of the tenth aspect of the present invention, in the compressor of the ninth aspect, the concave portion includes a first cylindrical space closer to the compression mechanism and a second cylindrical space farther from the compression mechanism. The inner diameter of the first cylindrical space is smaller than the inner diameter of the second cylindrical space. According to this structure, the structure of the recessed portion is complicated. Therefore, the moving distance and moving time of the high-pressure refrigerant are further increased, thereby reliably suppressing the discharge of refrigerating machine oil from the compressor. [Effects of the Invention] According to the compressors of the first, sixth, seventh, eighth, ninth, and tenth viewpoints of the present invention, the discharge of refrigerating machine oil from the compressor is suppressed. According to the compressor of the second aspect of the present invention, the high-speed rotation of the rotor becomes easy. According to the compressor of the third aspect of the present invention, the output capacity of the compressor is increased. According to the compressor of the fourth aspect of the present invention, the high-pressure refrigerant can stably reach the surface of the rotor. According to the compressor of the fifth aspect of the present invention, the refrigerating machine oil stored under the casing can be used for lubrication of the sliding parts of the compression mechanism.

Hereinafter, an embodiment of the air conditioner of the present invention will be described using drawings. In addition, the specific configuration of the air conditioner of the present invention is not limited to the following embodiments, and can be appropriately changed without departing from the gist of the invention. (1) Overall structure (1-1) Overview Fig. 1 shows a compressor 5 according to an embodiment of the present invention. The compressor 5 is installed in refrigerating devices such as air conditioners and refrigerators to compress gaseous refrigerant. The compressor 5 has a housing 10, a motor 20, a crankshaft 30, and a compression mechanism 40. (1-2) Housing 10 The housing 10 contains other components of the compressor 5, and can withstand the high pressure of the refrigerant. The housing 10 has a cylindrical part 11, an upper part 12 and a lower part 13. The cylindrical portion 11 is the largest among the constituent elements of the housing 10, and has a cylindrical shape. Both the upper part 12 and the lower part 13 are joined to the cylindrical part 11. Below the casing 10, an oil storage portion 14 for storing refrigerating machine oil 141 is provided. A suction pipe 15 is provided in the cylindrical portion 11. A discharge pipe 16 and a terminal 17 are provided on the upper part 12. The suction pipe 15 is used to suck low-pressure refrigerant. The ejection pipe 16 is used to eject high-pressure refrigerant. The terminal 17 receives power supply from the outside. (1-3) Motor 20 The motor 20 generates mechanical power using electric power supplied from the terminal 17 via a wire (not shown). The motor 20 has a stator 21 and a rotor 22. As shown in FIG. 2, the stator 21 has a cylindrical shape and is fixed to the cylindrical portion 11 of the housing 10. A gap 23 is formed between the stator 21 and the rotor 22. The gap 23 functions as a passage for the refrigerant. As shown in FIG. 3, the stator 21 has a stator core 21a, an insulator 21b, and a winding 21c. The stator core 21a includes a plurality of laminated steel plates. A space 213 for arranging the rotor 22 is formed in the stator core 21a. The insulator 21b contains resin. The insulator 21b is respectively disposed on the upper surface 211 of the stator core and the lower surface 212 of the stator core. The winding 21c is used to emit an alternating magnetic field, and is wound on the laminated body of the stator core 21a and the insulator 21b. As shown in FIG. 4, the rotor 22 has a rotor core 22a, a permanent magnet 22b, an end plate 22c, a balance weight 22d, and a bolt 22e. The rotor core 22a includes a plurality of laminated steel plates. A space 223 for fixing the crankshaft 30 is formed in the rotor core 22a. The permanent magnet 22b is used to rotate the rotor 22 as a whole by interacting with the alternating magnetic field emitted by the winding 21c. The permanent magnet 22b is disposed in the cavity 224 of the rotor core 22a. The end plates 22c are respectively disposed on the upper surface 221 of the rotor core and the lower surface 222 of the rotor core to prevent the permanent magnet 22b from leaving the cavity 224. The balance weight 22d is used to adjust the center of gravity of the rotating body including the rotor 22 and the parts rotating with the rotor 22. The balance weight 22d is provided on either end plate 22c. The bolt 22e fixes the end plate 22c or the balance weight 22d to the rotor core 22a. (1-4) Crankshaft 30 Returning to FIG. 1, the crankshaft 30 is used to transmit the power generated by the motor 20 to the compression mechanism 40. The crankshaft 30 rotates around the rotation axis RA. The crankshaft 30 has a main shaft portion 31 and an eccentric portion 32. A part of the main shaft portion 31 is fixed to the rotor 22. The eccentric portion 32 is eccentric with respect to the rotation axis RA. (1-5) Compression mechanism 40 The compression mechanism 40 compresses low-pressure refrigerant to generate high-pressure refrigerant. The compression mechanism 40 includes a cylinder 41, a piston 42, a front head 61, a rear head 62, and a silencer 45. The cylinder 41 is a metal member and has an internal space communicating with the outside of the housing 10 via the suction pipe 15. The piston 42 is a cylindrical metal member smaller than the cylinder 41. The piston 42 is mounted on the eccentric part 32. The eccentric portion 32 and the piston 42 are arranged in the internal space of the cylinder 41. As the crankshaft 30 rotates, the piston 42 revolves. The front head 61 is a member that blocks the upper side of the internal space of the cylinder 41. The front head 61 is fixed to the cylindrical portion 11. The front head 61 also has the function of supporting the bearing of the main shaft portion 31 above the eccentric portion 32. The rear head 62 is a member that blocks the lower side of the inner space of the cylinder 41. The rear head 62 also has the function of supporting the bearing of the main shaft portion 31 below the eccentric portion 32. The compression chamber 43 is defined by the cylinder 41, the piston 42, the front head 61, and the rear head 62. A muffler 45 is installed on the front head 61. The front head 61 and the muffler 45 define a muffler room. The volume of the compression chamber 43 is increased or decreased due to the revolution of the piston 42, whereby the low-pressure refrigerant is compressed to generate high-pressure refrigerant. The high-pressure refrigerant is ejected from the passage 44 formed in the front head 61 to the muffler chamber. A discharge valve (not shown) is provided in the passage 44. The discharge valve suppresses the backflow of the high-pressure refrigerant from the muffler chamber to the compression chamber 43. The high-pressure refrigerant passes through the passage 44 every time the piston 42 revolves. The intermittent passage of the high-pressure refrigerant passage 44 as described above may cause noise. The muffler 45 smoothes the pressure fluctuation of the gas refrigerant in the muffler chamber, thereby reducing noise. The high-pressure refrigerant is ejected from the ejection hole 46 formed in the muffler 45 to the outside of the compression mechanism 40. (2) Basic operation The arrows in Figure 1 indicate the flow of refrigerant. The low-pressure refrigerant is sucked from the suction pipe 15 into the compression chamber 43 of the compression mechanism 40. The high-pressure refrigerant generated by the compression operation of the compression mechanism 40 is discharged from the compression mechanism 40 through the passage 44 and the discharge hole 46. After that, the high-pressure refrigerant is blown toward the rotor 22 and then advances toward the gap 23. After the high-pressure refrigerant rises along the gap 23, it is ejected from the ejection pipe 16 to the outside of the housing 10. (3) Detailed configuration The rotor 22 of the compressor 5 of the present invention is configured to rotate at 75 rps (rotation per second) or more and 150 rps or less. The rotation speed is faster than the rotation speed of the rotor in the previous compressor, which is 15~75 rps. FIG. 5 shows the dimensions of each part of the compressor 5. The first dimension D1 is the inner diameter of the cylindrical portion 11 of the housing 10. The second dimension D2 is the outer diameter of the rotor core 22a of the rotor 22. The ratio D1/D2 of the first dimension D1 to the second dimension D2 is designed to be 1.8 or less. For example, the first dimension D1 is 90 mm, and the second dimension is 50 mm. The ratio D1/D2 can also be designed to be "not reached" 1.8. The third dimension D3 is twice the distance S between the rotation axis RA of the rotor 22, which is an infinite straight line, and the ejection hole 46 of the compression mechanism 40 formed in the muffler 45 in a plan view. Here, the separation distance S in plan view refers to the point corresponding to the position of the ejection hole 46 on the vertical line extending perpendicular to the rotation axis RA, from the intersection of the rotation axis RA and the vertical line to the point equivalent to the ejection The distance to the point where the hole 46 is located. In other words, the distance S in a plan view is the shortest distance between the rotation axis RA and the point corresponding to the ejection hole 46. The ratio D3/D2 of the third dimension D3 to the second dimension D2 is designed to be 0.5 or less. Returning to Fig. 1, as the refrigerating machine oil 141 stored in the oil storage portion 14, a relatively low viscosity of 53 mm ² /s or less at a temperature of 40°C is used. The refrigerating machine oil 141 is as follows, for example. -Ether compound FVC50. -Ether compound FW50. -Other ether compounds. -Ester compounds. Furthermore, a specific amount of alkyl aromatic hydrocarbon may be added to the above-mentioned refrigerating machine oil. (4) Feature (4-1) Since the second dimension D2, which is the outer diameter of the rotor 22, is large, the high-pressure refrigerant moves along the lower surface of the rotor 22 for a long distance. During this movement, the oil droplets of the refrigerating machine oil 141 mixed with the high-pressure refrigerant have a chance to escape from the high-pressure refrigerant. Therefore, the discharge of the refrigerating machine oil 141 from the compressor 5 is suppressed. (4-2) The viscosity of refrigeration oil is relatively low. Therefore, since the sliding loss of the compression mechanism 40 can be reduced, the high-speed rotation of the rotor 22 becomes easy. (4-3) The rotor 22 rotates at a high speed. Therefore, the output capacity of the compressor 5 increases. (4-4) The high-pressure refrigerant discharged from the compression mechanism 40 first travels along the crankshaft 30. Therefore, the high-pressure refrigerant can stably reach the lower surface of the rotor 22. (4-5) The compression mechanism 40 is provided under the housing 10. Therefore, it is easy to use the refrigerating machine oil 141 stored under the casing 10 for lubrication of the sliding part of the compression mechanism 40. (4-6) The discharge pipe 16 and the compression mechanism 40 are located on opposite sides of each other with the motor 20 as a reference. Therefore, when the high-pressure refrigerant moves along the path from the compression mechanism 40 to the discharge pipe 16, the motor 20 functions as an obstacle. When the high-pressure refrigerant avoids the obstacle, the oil droplets of the refrigerating machine oil 141 mixed with the high-pressure refrigerant have a chance to escape from the high-pressure refrigerant. Therefore, the discharge of the refrigerating machine oil 141 from the compressor 5 is further suppressed. (4-7) The distance between the high-pressure refrigerant moving from the discharge hole 46 of the compression mechanism 40 to the outer edge of the rotor 22. During this movement, the oil droplets of the refrigerating machine oil 141 mixed with the high-pressure refrigerant have a chance to escape from the high-pressure refrigerant. Therefore, the discharge of the refrigerating machine oil 141 from the compressor 5 is further suppressed. (4-8) The high-pressure refrigerant moves along the lower surface of the rotor 22 by a distance of at least 50% of the radius of the rotor 22. Therefore, the discharge of the refrigerating machine oil 141 from the compressor 5 can be suppressed more reliably. (5) Modified Example (5-1) First Modified Example FIG. 6 shows a compressor 5A of the first modified example of the above-mentioned embodiment. The structure of the rotor 22 of the compressor 5A is different from the above-mentioned embodiment. As shown in FIG. 7, a recess 25 is formed on the lower surface 222 of the rotor core. According to this structure, the high-pressure refrigerant is temporarily accommodated in the recess 25 before reaching the gap 23 between the stator 21 and the rotor 22. Therefore, since the moving distance and moving time of the high-pressure refrigerant are increased, the discharge of the refrigerating machine oil 141 from the compressor 5A is further suppressed. (5-2) Second Modification Example FIG. 8 shows the compressor 5B of the second modification example of the above-mentioned embodiment. The structure of the compressor 5B-based rotor 22 is different from the above-mentioned embodiment. As shown in FIG. 9, a recess 25 is formed on the lower surface 222 of the rotor core. The recess 25 includes a first cylindrical space 251 closer to the compression mechanism 40 and a second cylindrical space 252 farther from the compression mechanism 40. The inner diameter B1 of the first cylindrical space 251 is smaller than the inner diameter B2 of the second cylindrical space 252. According to this structure, the structure of the recessed part 25 is complicated. Therefore, since the moving distance and moving time of the high-pressure refrigerant are further increased, the discharge of the refrigerating machine oil 141 from the compressor 5B can be reliably suppressed. (5-3) Third Modified Example The rotor 22 of the compressor 5 of the above-mentioned embodiment is configured to rotate at 75 rps or more and 150 rps or less. Alternatively, the rotor 22 may be configured to rotate at more than 75 rps and 150 rps or less. In this case, since the rotation speed is slightly faster than the rotation speed of the rotor 22 of the compressor 5 of the above embodiment, the output capacity of the compressor 5 can be slightly increased. Preferably, the rotor 22 may also be configured to rotate at 90 rps or more and 130 rps or less. In this case, the rotation speed is much faster than the rotation speed of the rotor 22 of the compressor 5 of the above embodiment, so the output capacity of the compressor 5 can be increased all the time. Furthermore, the rotor 22 may be configured to rotate at more than 90 rps and 130 rps or less. In this case, the rotation speed is faster, so the output capacity of the compressor 5 can be further increased. The third modification example can also be applied to the first modification example or the second modification example.

5‧‧‧Compressor 5A‧‧‧Compressor 5B‧‧‧Compressor 10‧‧‧Shell 11‧‧‧Cylinder part 12‧‧‧Upper part 13‧‧‧Lower part 14‧‧‧Oil storage part 15‧‧ ‧Suction pipe 16‧‧‧Ejection pipe 17‧‧‧Terminal 20‧‧‧Motor 21‧‧‧Stator 21a‧‧‧Stator core 21b‧‧‧Insulator 21c‧‧‧Winding 22‧‧‧Rotor 22a‧‧‧Rotor Core 22b‧‧‧Permanent magnet 22c‧‧‧End plate 22d‧‧‧Balance weight 22e‧‧‧Bolt 23‧‧‧Gap 24‧‧‧Gap 25‧‧‧Concavity 30‧‧‧Crankshaft 31‧‧‧Main shaft Part 32‧‧‧Eccentric part 40‧‧‧Compression mechanism 41‧‧‧Cylinder 42‧‧‧Piston 43‧‧‧Compression chamber 44‧‧‧Passage 45‧‧‧Muffler 46‧‧‧Ejection hole 61‧‧‧ Front head 62‧‧‧Rear head 141. ‧‧Space 224‧‧‧cavity 251‧‧‧First cylindrical space 252‧‧‧Second cylindrical space B1‧‧‧Inner diameter of the first cylindrical space B2‧‧‧Inside the second cylindrical space Diameter D1‧‧‧The first dimension D2‧‧‧The second dimension D3‧‧‧The third dimension RA‧‧‧Rotation axis S

Fig. 1 is a cross-sectional view of a compressor 5 according to an embodiment of the present invention. FIG. 2 is a plan view of the cylindrical portion 11 and the motor 20 of the compressor 5. FIG. 3 is a cross-sectional view of the stator 21 of the compressor 5. 4 is a cross-sectional view of the rotor 22 of the compressor 5. FIG. 5 is a partial cross-sectional view of the compressor 5. Fig. 6 is a cross-sectional view of a compressor 5A according to a first modification of the present invention. Fig. 7 is a cross-sectional view of the rotor 22 of the compressor 5A. Fig. 8 is a cross-sectional view of a compressor 5B according to a second modification of the present invention. Fig. 9 is a cross-sectional view of the rotor 22 of the compressor 5B.

10‧‧‧Shell

11‧‧‧Cylinder

21a‧‧‧Stator core

22a‧‧‧Rotor core

45‧‧‧Muffler

46‧‧‧Ejection hole

61‧‧‧Front Head

D1‧‧‧The first size

D2‧‧‧Second size

D3‧‧‧Dimension 3

RA‧‧‧Rotation axis

S‧‧‧distance

Claims (9)

A compressor (5A, 5B) comprising: a housing (10) including a cylindrical portion (12) having an inner diameter of a first dimension (D1); a motor (20) including a housing (10) having a second dimension (D2) ) Outer diameter rotor (22); and compression mechanism (40), which generates high-pressure refrigerant by compressing low-pressure refrigerant; the ratio of the first dimension to the second dimension (D1/D2) is 1.8 or less, In addition, on the surface (222) of the rotor facing the compression mechanism, a recess (25) for temporarily accommodating the high-pressure refrigerant discharged from the compression mechanism is formed. Such as the compressor (5B) of claim 1, wherein the recess (25) includes a first cylindrical space (251) closer to the compression mechanism and a second cylindrical space (252) farther from the compression mechanism, The inner diameter (B1) of the first cylindrical space is smaller than the inner diameter (B2) of the second cylindrical space. For example, the compressor of claim 1 or claim 2 further includes a refrigerating machine oil (141) having a viscosity of 53 mm ² /s or less at a temperature of 40°C, and the refrigerating machine oil is configured to lubricate the sliding parts of the compression mechanism. Such as the compressor of claim 1 or claim 2, wherein the rotor is configured to rotate at a rotation speed of 75 rps or more. For example, the compressor of claim 1 or claim 2, which further includes a crankshaft (30) that transmits power from the rotor to the compression mechanism, The compression mechanism ejects the high-pressure refrigerant along the crankshaft toward the rotor. Such as the compressor of claim 1 or claim 2, wherein the compression mechanism is arranged below the motor. For example, the compressor of claim 1 or claim 2, which further includes a discharge pipe (16) for discharging the high-pressure refrigerant to the outside of the housing, the discharge pipe is arranged above the motor, and the motor further includes a stator (21 ), the gap (24) between the stator and the rotor functions as a passage for the high-pressure refrigerant to pass through. Such as the compressor of claim 1 or claim 2, wherein the compression mechanism has an ejection hole (46) for ejecting the high-pressure refrigerant, which is the distance between the rotation axis (RA) of the rotor and the ejection hole in plan view (S The third dimension (D3) which is twice of) is smaller than the above-mentioned second dimension. Such as the compressor of claim 8, wherein the ratio of the third dimension to the second dimension (D3/D2) is 0.5 or less.

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