Scroll compressor having overheating prevention device

Abstract

A scroll compressor including a casing divided into a low pressure portion and a high pressure portion, a fixed scroll in the low pressure portion, an orbiting scroll, a motor to transmit driving force to the orbiting scroll, and an overheating prevention device that includes a body having a refrigerant discharge hole allowing the high pressure portion to communicate with the low pressure portion, and a bimetal valve between the high pressure portion and the low pressure portion to selectively open and close the refrigerant discharge hole to discharge a high temperature refrigerant of the high pressure portion through the refrigerant discharge hole to the low pressure portion based on the temperature of the high pressure portion being equal to or greater than a certain temperature. An overload breaker is operated by the high temperature refrigerant discharged through the refrigerant discharge hole to turn the motor off.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of International Application No. PCT / KR2023 / 017678, filed Nov. 6, 2023, and claims priority to Korean Application No. 10-2023-0000679, filed Jan. 3, 2023, and which are incorporated herein by reference in their entireties.TECHNICAL FIELD

[0002] The disclosure relates to a scroll compressor and more particularly, to a scroll compressor having an overheating prevention device.BACKGROUND ART

[0003] A compressor is a mechanical device for increasing a pressure by compressing air, a refrigerant, or other various working gases by using a motor. The compressor is variously used throughout the industrial fields.

[0004] If the compressor is used for a refrigerant cycle, the compressor may convert a refrigerant in a low pressure to the refrigerant in a high pressure and then, may retransmit the converted refrigerant to a condenser.

[0005] If the compressor is roughly divided, it may be divided into a reciprocating compressor in which a compression space where a working gas is sucked and discharged is formed between a piston and a cylinder, and the piston reciprocates in a straight line inside the cylinder to compress a refrigerant, a rotary compressor in which a compression space where the working gas is sucked and discharged is formed between an eccentrically rotating rolling piston and a cylinder, and the rolling piston rotates eccentrically along an inner wall of the cylinder to compress a refrigerant, and a scroll compressor in which a compression space where the working gas is sucked and discharged is formed between an orbiting scroll and a fixed scroll, and the orbiting scroll rotates along the fixed scroll to compress a refrigerant. The scroll compressor is widely used for a refrigeration cycle device because it has high efficiency, has low vibrations and noises, and is compact and lightweight compared to the reciprocating compressor or the rotary compressor.DISCLOSURETechnical Solution

[0006] According to an embodiment, a scroll compressor may include a casing, a high / low pressure separation cover dividing an inside of the casing into a low pressure portion and a high pressure portion, a fixed scroll disposed at the low pressure portion, an orbiting scroll which engages with the fixed scroll and orbits and which forms a compression chamber with the fixed scroll, a motor to transmit a driving force to the orbiting scroll, an overheating prevention device including a body having a refrigerant discharge hole allowing the high pressure portion to communicate with the low pressure portion, a bimetal valve positioned at a boundary portion between the high pressure portion and the low pressure portion, and a housing coupled to the body to restrict the bimetal valve to movement in an axial direction, so that the bimetal valve selectively opens and closes the refrigerant discharge hole according to a temperature of the high pressure portion and so that a high temperature refrigerant of the high pressure portion is discharged through the refrigerant discharge hole to the low pressure portion based on the temperature of the high pressure portion being equal to or greater than a certain temperature. An overload breaker may be disposed at the low pressure portion and which is operated by the high temperature refrigerant discharged through the refrigerant discharge hole and then from the overheating prevention device to turn the motor off. The body may be provided around the refrigerant discharge hole and include a valve seat disposed at a position lower than an upper surface of the high / low pressure separation cover.

[0007] The valve seat may be disposed to be further away from the high pressure portion than the upper surface of the high / low pressure separation cover.

[0008] The bimetal valve may be seated on the valve seat and include a protrusion closing the refrigerant discharge hole.

[0009] The valve seat may be disposed at the position lower than the upper surface of the high / low pressure separation cover.

[0010] The body of the overheating prevention device may be coupled in a direction from an inside of the high / low pressure separation cover to an outside of the high / low pressure separation cover.

[0011] The body of the overheating prevention device may be thread-fastened to the high / low pressure separation cover.

[0012] An internal pressure relief (IPR) valve coupled to the high / low pressure separation cover may be further included. A direction coupling the IPR valve to the high / low pressure separation cover may be the same direction as a direction coupling the body of the overheating prevention device to the high / low pressure separation cover.

[0013] A lower portion of the body of the overheating prevention device may be provided with a first grip surface to which a wrench is coupled. A lower part of the IPR valve may be provided with a second grip surface in the same size as that of the first grip surface.

[0014] The body of the overheating prevention device may be made of an insulation material.

[0015] The bimetal valve may include a refrigerant passage hole disposed around the protrusion.

[0016] According to an embodiment of the disclosure, an overheating prevention device is coupled to a high / low pressure separation cover dividing an inside of a casing of a scroll compressor into a low pressure portion and a high pressure portion. The overheating prevention device may include a body including a refrigerant discharge hole allowing the high pressure portion to communicate with the low pressure portion and a valve seat provided on a side of the refrigerant discharge hole, a bimetal valve including a protrusion which selectively opens and closes the refrigerant discharge hole according to a temperature of the high pressure portion, and a refrigerant passage hole positioned around the protrusion, and a housing coupled to the body to restrict the bimetal valve to movement in an axial direction. The valve seat is disposed at the position lower than the upper surface of the high / low pressure separation cover.DESCRIPTION OF DRAWINGS

[0017] FIG. 1 is a sectional view illustrating a scroll compressor according to an embodiment of the disclosure;

[0018] FIG. 2 is a perspective view viewing an overheating prevention device from an outside of a high / low pressure separation cover of a scroll compressor according to an embodiment of the disclosure;

[0019] FIG. 3 is a perspective view viewing an overheating prevention device from an inside of a high / low pressure separation cover of a scroll compressor according to an embodiment of the disclosure;

[0020] FIG. 4 is a perspective view illustrating an example of coupling an overheating prevention device of a scroll compressor to an inside of a high / low pressure separation cover according to an embodiment of the disclosure;

[0021] FIG. 5 is an exploded perspective view illustrating an overheating prevention device of a scroll compressor according to an embodiment of the disclosure;

[0022] FIG. 6 is an enlarged sectional view of part of FIG. 5;

[0023] FIG. 7 is a sectional view illustrating an example in which if a vale of an overheating prevention device of a scroll compressor is closed, a high pressure portion does not communicate with a low pressure portion according to an embodiment of the disclosure; and

[0024] FIG. 8 is a sectional view illustrating an example in which if a vale of an overheating prevention device of a scroll compressor is opened, a high pressure portion communicates with a low pressure portion according to an embodiment of the disclosure.Mode for Invention

[0025] Embodiments of the disclosure may be modified in various different forms and may have various embodiments, wherein specific embodiments are exemplified in the drawings and specifically explained in the detailed description. However, it should be noted that the various embodiments are not for limiting the scope of the disclosure to a specific embodiment but they should be interpreted to include all modifications, equivalents, and / or alternatives of the embodiments of the disclosure. With respect to the description of the drawings, similar components may be designated by similar reference numerals.

[0026] In case it is determined that in describing the disclosure, the detailed description of related known functions or configurations may unnecessarily confuse the gist of the disclosure, the detailed description thereof will be omitted.

[0027] In addition, the embodiments below may be modified in various different forms, and the scope of the technical idea of the disclosure is not limited to the embodiments below. Rather, these embodiments are provided to make the disclosure more sufficient and complete, and to fully convey the technical idea of the disclosure to those skilled in the art.

[0028] The terms used in the disclosure are used only to explain specific embodiments and are not intended to limit the scope of a right of the disclosure. A singular expression includes a plural expression, unless obviously differently defined in the context.

[0029] In the disclosure, the expression such as “have,”“may have,”“include”, or “may include” denotes the existence of such a characteristic (e.g. a numerical value, a function, an operation, or a component such as a part), and the expression does not exclude the existence of an additional characteristic.

[0030] In the disclosure, the expression “A or B”, “at least one of A and / or B”, “one or more of A and / or B”, or the like may include all possible combinations of the listed items. For example, “A or B”, “at least one of A and B”, or “at least one of A or B” may refer to all of a case including at least one A, a case including at least one B, or a case including all of at least one A and at least one B.

[0031] The expression “1st”, “2nd”, “first”, “second”, or the like used in the disclosure may be used to describe various elements regardless of any order and / or degree of importance, wherein the expression is used only to distinguish one element from another element and is not intended to limit the elements.

[0032] Also, the term ‘front end’, ‘rear end’, ‘upper part, ‘lower part’, ‘upper end’, ‘lower end’, or the like used in the disclosure is not defined based on the drawings and a shape and a position of each component is not limited by the relevant term.

[0033] Hereinafter, an example of a scroll compressor according to the disclosure is specifically described with reference to the appended drawings.

[0034] FIG. 1 is a sectional view illustrating a scroll compressor according to an embodiment of the disclosure.

[0035] With reference to FIG. 1, the scroll compressor 1 according to an embodiment of the disclosure may include a casing 10, a main frame 20, a fixed scroll 21, an orbiting scroll 23, a driving motor 30, and an overheating prevention device 100.

[0036] The casing 10 forms an appearance of the scroll compressor 1. The casing 10 may be formed with a closed container. The casing 10 may include a refrigerant inlet pipe 13 into which a refrigerant flows and a refrigerant outlet pipe 14 from which the refrigerant discharged. If the scroll compressor 1 forms a refrigeration cycle together with a condenser 2, an expansion value 3, and an evaporator 4, the refrigerant inlet pipe 13 may be connected to the evaporator 4, and the refrigerant outlet pipe 14 may be connected to the condenser 2.

[0037] The casing 10 may include an upper casing 11 and a lower casing 12. The upper casing 11 is coupled to an upper end of the lower casing 12 to form the casing 10.

[0038] The casing 10 may be formed by coupling the upper casing 11 and the lower casing 12. The casing 10 may close an inside of the casing 10, excluding the refrigerant inlet pipe 13 and the refrigerant outlet pipe 14. For example, the refrigerant may flow into the inside of the casing 10 or may be discharged from the casing 10 only through the refrigerant inlet pipe 13 and the refrigerant outlet pipe 14.

[0039] An inner space of the casing 10 may be divided by a high / low pressure separation cover 16 to form a low pressure portion (L) and a high pressure portion (H). For example, the lower casing 12 and the high / low pressure separation cover 16 forms the low pressure portion (L) inside the casing 10, and the upper casing 11 and the high / low pressure separation cover 16 may form the high pressure portion (H) inside the casing 10. Here, the low pressure portion (L) and the high pressure portion (H) refer to an area where there is a difference in pressures relative to the high / low pressure separation cover 16 if the scroll compressor 1 operates. Therefore, a high pressure may be applied to the high pressure portion (H), and a pressure lower than that of the high pressure portion (H) may be applied to the low pressure portion (L). If the scroll compressor 1 does not operate, pressures of the low pressure portion (L) and the high pressure portion (H) may be the same.

[0040] The refrigerant outlet pipe 14 may be provided for the upper casing 11. The refrigerant outlet pipe 14 may communicate with the high pressure portion (H) formed by the upper casing 11 and the high / low pressure separation cover 16. A high temperature / pressure refrigerant compressed by a compression portion of the scroll compressor 1 may be discharged from the high pressure portion (H) to the condenser 2 through the refrigerant outlet pipe 14.

[0041] The refrigerant inlet pipe 13 may be provided for the lower casing 12. The refrigerant inlet pipe 13 may communicate with the low pressure portion (L) formed by the lower casing 12 and the high / low pressure separation cover 16. A low temperature / pressure refrigerant provided from the evaporator 4 may flow into the low pressure portion (L) which is an inside of the lower casing 12 through the refrigerant inlet pipe 13.

[0042] The refrigerant may flow into the inside of the casing 10 through the refrigerant inlet pipe 13 and may be compressed by the fixed scroll 21, the orbiting scroll 23, and the driving motor 30 disposed inside the casing 10, wherein the compressed refrigerant may be discharged to an outside of the casing 10 through the refrigerant outlet pipe 14. The fixed scroll 21 and the orbiting scroll 23 may form a compression portion.

[0043] An oil storage tank 19 for receiving oil 18 may be provided for a lower portion of the lower casing 12. A base 15 for supporting the casing 10 may be provided for the lower portion of the lower casing 12. The scroll compressor 1 may be vertically installed with respect to a support surface 7 by the base 15.

[0044] A main frame 20 may be installed inside the casing 10. The main frame 20 may be fixed into the lower casing 12. For example, the main frame 20 may be installed in the low pressure portion (L) of the casing 10.

[0045] The main frame 20 may be formed such that the fixed scroll 21 may be installed. The main frame 20 may be formed to support the orbiting scroll 23. For example, the main frame 20 may be formed such that it supports the orbiting scroll 23 and the orbiting scroll 23 orbits around the main frame 20. The main frame 20 may be formed to rotatably support one end of a driving shaft 35.

[0046] The main frame 20 may include an oil pocket 20a for receiving oil. The oil pocket 20a is formed to receive oil supplied through an oil supply passage provided along a longitudinal direction of the driving shaft 35 inside the driving shaft 35. The main frame 20 may include an oil discharge passage for discharging oil received in the oil pocket 20a to an outside of the main frame 20. For example, the oil discharge passage may be formed in a radial direction of the main frame 20.

[0047] The fixed scroll 21 may be installed inside the casing 10. For example, the fixed scroll 21 may be installed inside the lower casing 12. The fixed scroll 21 may be installed at an upper side of the main frame 20. The fixed scroll 21 may be installed at an upper surface of the main frame 20 fixed to the lower casing 12. The fixed scroll 21 may be installed at an upper surface of the main frame 20 with a plurality of bolts.

[0048] If the fixed scroll 21 is installed at the upper side of the main frame 20, a space where the orbiting scroll 23 may be installed is formed between the fixed scroll 21 and the main frame 20.

[0049] The fixed scroll 21 may include a wrap receiving portion 21a, a flange 21d provided around the wrap receiving portion 21a, and a fixed wrap 21c provided for an inner space 21b of the wrap receiving portion 21a. The wrap receiving portion 21a may be formed in a container shape which may be received inside the casing 10. An upper surface of the inner space 21b of the wrap receiving portion 21a, for example, an upper surface of an inside of the wrap receiving portion 21a which faces or contacts an upper end of the orbiting scroll 23 may be formed as a mirror surface to minimize friction with the orbiting scroll 23. The inner space 21b of the wrap receiving portion 21a may form a compression chamber. The fixed wrap 21c is vertically extended downwardly from the upper surface of the inside of the wrap receiving portion 21a and may be formed in a spiral shape. The fixed wrap 21c may be formed as a curved surface having a certain thickness and height.

[0050] The fixed wrap 21c may include an inlet into which a refrigerant of the low pressure portion (L) flows and an outlet 21e from which the refrigerant is discharged. The inlet may be formed at one side of the fixed scroll 21, for example, one side of the wrap receiving portion 21a to penetrate the wrap receiving portion 21a. The inner space 21b of the wrap receiving portion 21a and the low pressure portion (L) of the casing 10 may be communicated through the inlet. Therefore, the refrigerant of the low pressure portion (L) may flow into the compression chamber of the wrap receiving portion 21a through the inlet. The outlet 21e is formed at the center of the upper surface of the fixed scroll 21 and discharges the refrigerant compressed in the compression chamber.

[0051] The orbiting scroll 23 may be installed to orbit around the fixed scroll 21 below the fixed scroll 21. The orbiting scroll 23 may be installed at the upper side of the main frame 20, a thrust surface 20b of the main frame 20 may support the orbiting scroll 23.

[0052] The orbiting scroll 23 may include an orbiting plate 23a, an orbiting wrap 23b, and a boss portion 23c. The orbiting plate 23a may be formed in a disc shape having a certain thickness and area. An upper surface of the orbiting plate 23a facing the fixed scroll 21 may be formed as a mirror surface for minimizing friction with the fixed wrap 21c of the fixed scroll 21. The orbiting wrap 23b may be vertically extended from the upper surface of the orbiting plate 23a and may be formed in a spiral shape. The orbiting wrap 23b is formed to mesh with the fixed wrap 21c of the fixed scroll 21. The boss portion 23c may be formed at the center of a lower surface of the orbiting plate 23a. An upper end of the driving shaft 35 may be inserted into the inner space 23d of the boss portion 23c. For example, the upper end of the driving shaft 35 may be coupled to the boss portion 23c.

[0053] The orbiting wrap 23b of the orbiting scroll 23 may engage with the fixed wrap 21c of the fixed scroll 21, and the boss portion 23c may be inserted into the oil pocket 20a of the main frame 20.

[0054] The lower surface of the orbiting plate 23a where the boss portion 23c is formed may be supported by the thrust surface 20b of the main frame 20. Therefore, the lower surface of the orbiting plate 23a supported by the thrust surface 20b of the main frame 20 may be also formed as a mirror surface to minimize friction with the thrust surface 20b.

[0055] The fixed wrap 21c of the fixed scroll 21 and the orbiting wrap 23b of the orbiting scroll 23 may be received to the wrap receiving portion 21a of the fixed scroll 21.

[0056] The fixed wrap 21c of the fixed scroll 21 and the orbiting wrap 23b of the orbiting scroll 23 which are mutually engaged with each other forms a plurality of compression pockets. If the orbiting scroll 23 rotates, the plurality of compression pockets move to the center of the wrap receiving portion 21a to compress a refrigerant flowing into the inlet of the fixed scroll 21 and discharge the same to the outlet 21e.

[0057] A rotation prevention mechanism for preventing the orbiting scroll 23 from rotating may be installed between the orbiting scroll 23 and the main frame 20. For example, an oldham ring may be used as the rotation prevention mechanism.

[0058] The orbiting scroll 23 may rotate by the driving shaft 35. One end of the driving shaft 35 may be coupled to the boss portion 23c of the orbiting scroll 23. The driving shaft 35 may rotate by the driving motor 30.

[0059] The driving motor 30 may include a stator 31 and a rotator 32. The stator 31 may be fixed to the inside of the casing 10. The stator 32 may be rotatably inserted into an inside of the stator 31. The driving shaft 35 may be inserted into the stator 32 to penetrate the same. The stator 32 may be fixed to the driving shaft 35. Therefore, the stator 32 and the driving shaft 35 may rotate integrally.

[0060] The driving shaft 35 may include an axial portion 35a formed to have a certain length and an eccentric portion 35b formed to be extended upwardly from an upper end of the axial portion 35a. For example, the upper end of the driving shaft 35 may be formed as the eccentric portion 35b. The axial portion 35a and the eccentric portion 35b may be eccentric to each other. For example, a central axis of the eccentric portion 35b may be spaced apart from a rotation center of the driving shaft, that is, a central axis of the axial portion 35a at a certain distance.

[0061] The stator 32 of the driving motor 30 may be fixed to the axial portion 35a of the driving shaft 35. One end of the axial portion 35a may be inserted into the main frame 20 and may be rotatably supported by bearing metal provided on the main frame 20.

[0062] The upper end of the driving shaft 35, that is, the eccentric portion 35b may be inserted into the boss portion 23c of the orbiting scroll 23. A bearing may be installed between the eccentric portion 35b of the driving shaft 35 and the boss portion 23c of the orbiting scroll 23.

[0063] A lower portion of the axial portion 35a may be rotatably supported by a sub frame 27 installed in the casing 10. The sub frame 27 may be fixed to the lower casing 12 and may be spaced apart from the main frame 20 downwardly at a certain distance. The sub frame 27 may include a support bearing 28 which may rotatably support a lower end of the driving shaft 35. For example, the support bearing 28 may be formed as bearing metal. Therefore, the driving shaft 35 may be supported by both ends of the main frame 20 and the sub frame 27 to rotate. For example, part of the upper side of the driving shaft 35 may be supported by the main frame 20, and the lower end of the driving shaft 35 may be supported by the sub frame 27.

[0064] The driving shaft 35 may include an oil supply passage therein. For example, the oil supply passage may be formed to penetrate the axial portion 35a and the eccentric portion 35b of the driving shaft 35.

[0065] An exit of the oil supply passage may be provided on an upper end of the eccentric portion 35b. Therefore, oil moving through the oil supply passage may be discharged to the inner space 23d of the boss portion 23c of the orbiting scroll 23 through the exit of the oil supply passage. Therefore, oil moving through the oil supply passage may be discharged to the inner space 23d of the boss portion 23c of an upper side of the eccentric portion 35b of the driving shaft 35.

[0066] An oil supply device 35d which supplies oil 18 of the oil storage tank 19 to an oil supply passage may be installed at a lower end of the driving shaft 35. The lower end of the oil supply device 35d may sink to the oil storage tank 19 of the casing 10. Therefore, if the driving shaft 35 rotates, oil 18 stored in the oil storage tank 19 may be supplied to the oil supply passage of the driving shaft 35 by a pressure applied to the oil storage tank 19 and the oil supply device 35d. The oil moving along the oil supply passage may be supplied to the inner space 23d of the boss portion 23c of the orbiting scroll 23.

[0067] A discharge guide 41 for guiding a refrigerant compressed in the compression chamber to the high pressure portion (H) may be installed at an upper surface of the fixed scroll 21. A back pressure actuator 43 may be installed at an upper side of the discharge guide 41. The back pressure actuator 43 is provided to cover an upper portion of the discharge guide 41. A first check valve 45 which selectively opens and closes the outlet 21e of the fixed scroll 21 may be installed between the discharge guide 41 and the fixed scroll 21.

[0068] The high / low pressure separation cover 16 for dividing an inside of the casing 10 into the low pressure portion (L) and the high pressure portion (H) may be installed at an upper side of the back pressure actuator 43. The back pressure actuator 43 may be installed to selectively contact the high / low pressure separation cover 16.

[0069] The high / low pressure separation cover 16 is installed inside the casing 10 and divides the inside of the casing 10 into the low pressure portion (L) and the high pressure portion (H). The high / low pressure separation cover 16 may include an upper outlet 34 allowing the low pressure portion (L) to communicate with the high pressure portion (H). The high / low pressure separation cover 16 may include a second check valve 33 which selectively opens and closes the upper outlet 34. The second check valve 33 may allow a refrigerant to flow in only one direction from the low pressure portion (L) to the high pressure portion (H).

[0070] The refrigerant compressed in the compression chamber of the fixed scroll 21 may be discharged to the high pressure portion (H) through the discharge guide 41, the back pressure actuator 43, and the high / low pressure separation cover 16. The refrigerant discharged to the high pressure portion (H) may be discharged to the outside of the casing 10 through the refrigerant outlet pipe 14.

[0071] Meanwhile, as above, when the refrigerant is compressed between the fixed scroll 21 and the orbiting scroll 23 in driving, a temperature of the high pressure portion (H) may increase to a setting temperature or higher. Due to the above, the scroll compressor 1 may be overheated, the driving motor 30 and many parts disposed inside the casing 10 may be damaged or deteriorated. According to an embodiment of the disclosure, the scroll compressor 1 may resolve the problem through the overheating prevention device 100 provided to the high / low pressure separation cover 16.

[0072] For example, the overheating prevention device 100 may allow the high pressure portion (H) to communicate with the low pressure portion (L) if the temperature of the high pressure portion (H) increases to the setting temperature or higher. In this case, the high temperature refrigerant of the high pressure portion (H) may flow into the low pressure portion (L) through the overheating prevention device 100. An overload breaker 50 installed in the low pressure portion (L) may operate by the high temperature refrigerant to stop the scroll compressor 1. As above, the overheating prevention device 100 may prevent overheating of the scroll compressor 1 to prevent the scroll compressor 1 from being damaged.

[0073] Hereinafter, a structure of the overheating prevention device 100 according to an embodiment of the disclosure is specifically described with reference to the drawings.

[0074] FIG. 2 is a perspective view viewing an overheating prevention device from an outside of a high / low pressure separation cover of a scroll compressor according to an embodiment of the disclosure. FIG. 3 is a perspective view viewing an overheating prevention device from an inside of a high / low pressure separation cover of a scroll compressor according to an embodiment of the disclosure. FIG. 4 is a perspective view illustrating an example of coupling an overheating prevention device of a scroll compressor to an inside of a high / low pressure separation cover according to an embodiment of the disclosure.

[0075] With reference to FIG. 2, the overheating prevention device 100 may be provided to the high / low pressure separation cover 16. For example, the overheating prevention device 100 may be separably coupled to the high / low pressure separation cover 16 and particularly, to a first fastening hole 16a of the high / low pressure separation cover 16 in a threaded fastening method. In the disclosure, in order to couple the overheating prevention device 100 to the high / low pressure separation cover 16, the threaded fastening method is described as an example, but the disclosure is not limited thereto and the overheating prevention device 100 may be coupled to the high / low pressure separation cover 16 in a bolting method or welding method which uses a plurality of bolts.

[0076] In the high / low pressure separation cover 16, an IPR valve 60 may be mounted onto a second fastening hole 16b of the high / low pressure separation cover 16. The IPR valve 60 may operate if a pressure of the high pressure portion (H) rapidly increases and reaches a certain pressure or more, and may allow the refrigerant of the high pressure portion (H) to bypass the high pressure portion to arrive at the low pressure portion (L).

[0077] As above, because the IPR valve 60 maintains the pressure of the high pressure portion (H) at less than the certain pressure, the scroll compressor 1 may operate smoothly and continuously.

[0078] Meanwhile, the overheating prevention device 100, if the temperature of the high pressure portion (H) is the certain temperature or higher, allows the high temperature refrigerant of the high pressure portion (H) to be discharged to the overload breaker 50 to operate the overload breaker 50. The scroll compressor 1, as the motor 30 is turned off by the overload breaker 50, stops operating.

[0079] With reference to FIG. 3, the overheating prevention device 100 may be assembled in a direction from an inside of the high / low pressure separation cover 16 to an outside of the high / low pressure separation cover 16. Accordingly, an upper portion of the overheating prevention device 100 may be coupled to the high / low pressure separation cover 16 and a lower portion thereof may be positioned at the low pressure portion (L).

[0080] With reference to FIG. 4, the overheating prevention device 100 may include a body 110 made of an insulation material. A first thread 111 may be formed along an outer circumference on an upper portion of the body 110, and a second thread 16a′ may be formed on an inner circumference of the first fastening hole 16a of the high / low pressure separation cover 16. Accordingly, the upper portion of the body 110 may be thread-fastened to the first fastening hole 16a of the high / low pressure separation cover 16.

[0081] A sealing member 170 may be disposed between the high / low pressure separation cover 16 and the body 110. The sealing member 170 may prevent the refrigerant from leaking between the high / low pressure separation cover 16 and the body 110. The sealing member 170 may be made of an insulation member. In this case, the sealing member 170 may prevent or minimize heat conducted from the high / low pressure separation cover 16 to the body 110.

[0082] FIG. 5 is an exploded perspective view illustrating an overheating prevention device of a scroll compressor according to an embodiment of the disclosure. FIG. 6 is an enlarged sectional view of part of FIG. 5.

[0083] The overheating prevention device 100 may include a body 110, a bimetal valve 130 seated on the body 110, and a housing 150 preventing the bimetal valve 130 from being completely separated from the body 110.

[0084] The body 110 may include a valve seat 113 on which the bimetal valve 130 is seated on its upper portion and a refrigerant discharge hole 115 which penetrate the body 110. The valve seat 113 may be disposed along a circumference of the refrigerant discharge hole 115. The refrigerant discharge hole 115 may be closed or opened by the bimetal valve 130.

[0085] If the refrigerant discharge hole 115 is opened by the bimetal valve 130, the high temperature refrigerant present in the high pressure portion (H) may be discharged to the low pressure portion (L) through the refrigerant discharge hole 115. In this case, the body 110 may be disposed at an upper side of the overload breaker 50 in a direction vertical to the overload breaker 50 (see FIG. 1) in order that the refrigerant discharged through the refrigerant discharge hole 115 may direct to the overload breaker 50 (see FIG. 1).

[0086] The overload breaker 50 may convert the motor 30 in driving to be in an off state while detecting the high temperature refrigerant with a temperature sensor disposed therein.

[0087] The body 110 may include a stepped portion 117 surrounding the valve seat 113 at a position spaced apart from the surrounding of the valve seat 113 at a certain distance. The stepped portion 117 may be at a position higher than the valve seat 113. When the bimetal valve 130 is affected and deformed by the temperature of the high pressure portion (H), an edge of the bimetal valve 130 may be supported by the stepped portion 117 (see FIG. 8). In this case, the bimetal valve 130 may open the refrigerant discharge hole 115.

[0088] The body 110 may include a flange 118 in contact with the sealing member 170. If the body 110 is fastened to the high / low pressure separation cover 16, the flange 118 may press the sealing member 170 to the inside of the high / low pressure separation cover 16 (see FIG. 7). Accordingly, the sealing member 170 may prevent the refrigerant from leaking between the high / low pressure separation cover 16 and the body 110.

[0089] The body 110 may include a grip surface 119 formed at a lower portion of the body 110 to be easily fastened to the high / low pressure separation cover 16 by using a tool, for example, a wrench. The grip surface 119 of the body 110 may be formed in various shapes. For example, it may be formed in a hexagonal shape corresponding to a hexagonal wrench.

[0090] The grip surface 119 of the body 110 may be formed in the same size as that of a grip surface 61 formed at a lower portion of the IPR valve 60. In this case, a worker may mount the IPR valve 60 and the body 110 of the overheating prevention device 100 onto the high / low pressure separation cover 16 by using a wrench of the same size. Also, the IPR valve 60 and the overheating prevention device 100 are fastened to the high / low pressure separation cover 16 in the same direction, and thus assembly efficiency may be improved.

[0091] The bimetal valve 130 may include a protrusion 131 which is formed approximately in a circle and protrudes in one side at the center, and a plurality of refrigerant passage holes 135 disposed at a certain interval along the surrounding of the protrusion 131.

[0092] The bimetal valve 130 may include the first metal layer 130a and the second metal layer 130b which are coupled to each other as shown in FIG. 6. The first metal layer 130a and the second metal layer 130b may be metal of which coefficients of thermal expansion are different. The bimetal valve 130 may be seated on the body 110 in a state that the first metal layer 130a directs to the low pressure portion (L) and the second metal layer 130b directs to the high pressure portion (H).

[0093] The protrusion 131 of the bimetal valve 130 may be seated on a valve seat 133. In this case, the refrigerant discharge hole 115 may be closed by the protrusion 131 of the bimetal valve 130. If the bimetal valve 130 is affected and deformed by the temperature of the high pressure portion (H), the protrusion 131 of the bimetal valve 130 may be spaced apart from the valve seat 113. Accordingly, the refrigerant discharge hole 115 may be opened.

[0094] The bimetal valve 130, when the temperature of the high pressure portion (H) is less than a certain temperature (a normal operating condition), may have a first shape for closing the refrigerant discharge hole 115 by the protrusion 131. The bimetal valve 130, when the temperature of the high pressure portion (H) is equal to or greater than a certain temperature (an overheating condition), may have a second shape for opening the refrigerant discharge hole 115 as its shape is deformed to the second shape different from the first shape.

[0095] The plurality of refrigerant passage holes 135 of the bimetal valve 130 may be a passage through which the refrigerant of the high pressure portion (H) may move to the refrigerant discharge hole 115.

[0096] The housing 150 may be formed approximately in a circle and may be coupled to an upper portion of the body 110. For example, a lower portion 151 of the housing 150 may be bonded to the stepped portion 117 of the body 110. Otherwise, because the upper portion of the body 110 may be formed as a groove, the housing 150 may be coupled in a state that the lower portion 151 of the housing 150 is pressed into the groove formed at the upper portion of the body 110.

[0097] The housing 150 may restrict the bimetal valve 130 in an axial direction in a state that the bimetal valve 130 is not completely separated from the body 110. Here, the axial direction may be a longitudinal direction of the refrigerant discharge hole 115.

[0098] A refrigerant inflow hole 153 may be provided at the center of the housing 150. The refrigerant of the high pressure portion (H) may flow into the plurality of refrigerant passage holes 135 of the bimetal valve 130 through the refrigerant inflow hole 153. In order that the bimetal valve 130 does not exit through the refrigerant inflow hole 153, the refrigerant inflow hole 153 may have a diameter smaller than that of the bimetal valve 130.

[0099] FIG. 7 is a sectional view illustrating an example in which if a vale of an overheating prevention device of a scroll compressor is closed, a high pressure portion does not communicate with a low pressure portion according to an embodiment of the disclosure. FIG. 8 is a sectional view illustrating an example in which if a vale of an overheating prevention device of a scroll compressor is opened, a high pressure portion communicates with a low pressure portion according to an embodiment of the disclosure. With reference to FIG. 7, the bimetal valve 130, when the protrusion 131 is seated on the valve seat 113 of the body 110, may close the refrigerant discharge hole 115. In this case, the high / low pressure separation cover 16 and the valve seat 113 may be positioned at different heights. For example, a height (V1) of the valve seat 113 may be placed at a position lower than a height V2 of an upper surface of the high / low pressure separation cover 16. Accordingly, the bimetal valve 130 may be disposed at a position lower than the upper surface of the high / low pressure separation cover 16 by a certain distance G. As above, the bimetal valve 130 may not be positioned at the high pressure portion (H) but may be positioned at a boundary portion between the high pressure portion (H) and the low pressure portion (L).

[0100] If the height (V1) of the valve seat 113 is at a position higher than the height V2 of the upper surface of the high / low pressure separation cover 16, the bimetal valve 130 is positioned within the high pressure portion (H). Under the normal operating condition (for example, in a state that the bimetal valve 130 closes a refrigerant outflow hole 115), if the refrigerant of the low pressure portion (L) fills the refrigerant outflow hole 115, the low pressure refrigerant is affected and overheated by the temperature of the high pressure portion (H) and volumetric efficiency is lowered due to reduced density. In the disclosure, if the bimetal valve 130 is positioned at the boundary portion between the high pressure portion (H) and the low pressure portion (L), it may be prevented that the refrigerant of the low pressure portion (L) is overheated by the temperature of the high pressure portion (H). Therefore, the overheating prevention device 100 according to the disclosure may prevent volumetric efficiency of the refrigerant of the low pressure portion (L) from being lowered in advance to improve a performance of the compressor.

[0101] Also, if the scroll compressor 1 operates, the oil 18 lubricates each part disposed inside the casing 10 by the driving shaft 35. Part of the oil 18 may mix with the refrigerant and flow from the low pressure portion (L) into the high pressure portion (H). Part of oil flowing into the high pressure portion (H) may move along the refrigeration cycle together with the refrigerant, and the other oil may flow down along an inner wall of the upper casing 11 and accumulate in an upper portion of the overheating prevention device 100.

[0102] For example, as shown in FIG. 7, the oil 18-1 may accumulate between the body 110 and a side of the housing 150, and the oil 18-2 may accumulate between the body 110 and a lower surface of the bimetal valve 130. As above, in the normal operating state, the refrigerant outflow hole 115 is closed by the bimetal valve 130, and airtightness of the refrigerant discharge hole 115 may be more firmly maintained by the oil 18-1, 18-2 accumulating in the upper portion of the overheating prevention device 100.

[0103] With reference to FIG. 8, if a temperature of the high pressure portion (H) is equal to or greater than a certain temperature (an overheated state), as a shape of the bimetal valve 130 is deformed, the protrusion 131 may be spaced apart from the valve seat 113 and the refrigerant discharge hole 115 may be opened.

[0104] In this case, the high temperature refrigerant present in the high pressure portion (H) sequentially passes through the refrigerant inflow hole 153 of the housing 150, the plurality of refrigerant passage holes 135 of the bimetal valve 130, and the refrigerant discharge hole 115 and is discharged to the low pressure portion (L).

[0105] The overload breaker 50 positioned at a lower side of the overheating prevention device 100 operates by the high temperature refrigerant discharged from the refrigerant discharge hole 115 and turns the motor 30 off. Accordingly, the scroll compressor 1 of the disclosure may stop operating to prevent damages due to overheating.

[0106] As above, the disclosure is shown and described with reference to various examples, but it may be appreciated by those skilled in the art that various modifications may be made in shapes and detailed matters without deviating from the scope of the disclosure defined by the appended claims and equivalents thereof.

Claims

1. A scroll compressor comprising:a casing;a high / low pressure separation cover dividing an inside of the casing into a low pressure portion and a high pressure portion;a fixed scroll disposed at the low pressure portion;an orbiting scroll which engages with the fixed scroll and orbits and which forms a compression chamber with the fixed scroll;a motor to transmit a driving force to the orbiting scroll;an overheating prevention device including:a body having a refrigerant discharge hole allowing the high pressure portion to communicate with the low pressure portion,a bimetal valve positioned at a boundary portion between the high pressure portion and the low pressure portion, anda housing coupled to the body to restrict the bimetal valve to movement in an axial direction,so that the bimetal valve selectively opens and closes the refrigerant discharge hole according to a temperature of the high pressure portion and so that a high temperature refrigerant of the high pressure portion is discharged through the refrigerant discharge hole to the low pressure portion based on the temperature of the high pressure portion being equal to or greater than a certain temperature; andan overload breaker which is disposed at the low pressure portion, and which is operated by the high temperature refrigerant discharged through the refrigerant discharge hole and then from the overheating prevention device to turn the motor off.

2. The scroll compressor of claim 1, wherein the body is around the refrigerant discharge hole and includes a valve seat disposed at a position lower than an upper surface of the high / low pressure separation cover.

3. The scroll compressor of claim 2, wherein the valve seat is disposed to be further away from the high pressure portion than the upper surface of the high / low pressure separation cover.

4. The scroll compressor of claim 2, wherein the bimetal valve is seated on the valve seat and includes a protrusion configured to close the refrigerant discharge hole.

5. The scroll compressor of claim 4, wherein the valve seat is disposed at the position lower than the upper surface of the high / low pressure separation cover.

6. The scroll compressor of claim 1, wherein the body of the overheating prevention device is coupled in a direction from an inside of the high / low pressure separation cover to an outside of the high / low pressure separation cover.

7. The scroll compressor of claim 6, wherein the body of the overheating prevention device is thread-fastened to the high / low pressure separation cover.

8. The scroll compressor of claim 6, further comprising:an internal pressure relief (IPR) valve coupled to the high / low pressure separation cover,wherein a direction coupling the IPR valve to the high / low pressure separation cover is the same direction as a direction coupling the body of the overheating prevention device to the high / low pressure separation cover.

9. The scroll compressor of claim 8, whereina lower portion of the body of the overheating prevention device is provided with a first grip surface to which a wrench is coupled, anda lower part of the IPR valve is provided with a second grip surface in the same size as that of the first grip surface.

10. The scroll compressor of claim 1, wherein the body of the overheating prevention device is made of an insulation material.

11. The scroll compressor of claim 4, wherein the bimetal valve includes a refrigerant passage hole disposed around the protrusion.

12. An overheating prevention device coupled to a high / low pressure separation cover dividing an inside of a casing of a scroll compressor into a low pressure portion and a high pressure portion, the overheating prevention device comprising:a body including a refrigerant discharge hole allowing the high pressure portion to communicate with the low pressure portion and a valve seat provided on a side of the refrigerant discharge hole;a bimetal valve including a protrusion which selectively opens and closes the refrigerant discharge hole according to a temperature of the high pressure portion, and a refrigerant passage hole positioned around the protrusion; anda housing coupled to the body to restrict the bimetal valve to movement in an axial direction,wherein the valve seat is disposed at a position lower than an upper surface of the high / low pressure separation cover.

13. The overheating prevention device of claim 12, wherein the bimetal valve is positioned at a boundary portion between the high pressure portion and the low pressure portion.

14. The overheating prevention device of claim 12, wherein the bimetal valve is disposed to be further away from the high pressure portion than the upper surface of the high / low pressure separation cover.

15. The overheating prevention device of claim 12, wherein the body of the overheating prevention device is coupled in a direction from an inside of the high / low pressure separation cover to an outside of the high / low pressure separation cover.

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