Electric valve and refrigeration cycle device

Abstract

Provided are an electrically operated valve capable of suppressing a decrease in durability, and a refrigeration cycle device having the electrically operated valve and using a natural refrigerant. The electric valve (1) is assembled in a refrigeration cycle device using a natural refrigerant. The electric valve (1) is provided with a valve element (30), a driving mechanism (40) for driving the valve element (30), and a shell (20), wherein the driving mechanism (40) is arranged on the inner side of the shell (20). A natural refrigerant is introduced into the inside of the housing (20). The drive mechanism (40) has a drive shaft (41) having a male thread (42t), and a bearing member (45) having a female thread (45t) screwed with the male thread (42t). Fluorine grease is applied to the drive shaft (41) and the bearing member (45).

Description

TECHNICAL FIELD

[0001] The present application relates to an electric valve and a refrigeration cycle device. BACKGROUND

[0002] Patent Literature 1 discloses a conventional electric valve. The electric valve of Patent Literature 1 is assembled to a refrigeration cycle device, for example, for flow control of refrigerant. The electric valve has a housing, a magnetic rotor, a speed reduction mechanism, a drive shaft, a bearing member, and a valve core. The magnetic rotor, the speed reduction mechanism, the drive shaft, and the bearing member are disposed inside the housing. Refrigerant is introduced into the inside of the housing. The magnetic rotor is connected to the drive shaft via the speed reduction mechanism. The drive shaft has an external thread. The bearing member has an internal thread that is screwed to the external thread. When the drive shaft is rotated, the drive shaft moves in the axial direction. Along with the movement of the drive shaft, the valve core moves in the axial direction. The drive shaft, the bearing member, and the gear of the speed reduction mechanism are sliding members, and grease is applied to the sliding members.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2012-197849

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] In a refrigeration cycle device, sometimes a natural refrigerant is used. The natural refrigerant is composed mainly of carbon dioxide or propane, for example. Compared with a hydrofluorocarbon (HFC) refrigerant used in most refrigeration cycle devices, the natural refrigerant flows in a high-pressure state.

[0008] The base oil of the grease applied to the sliding members of the electric valve is composed mainly of mineral oil or synthetic oil (ether-based oil, ester-based oil, etc.). Therefore, the compatibility of the grease with refrigeration oil flowing with the refrigerant is relatively high, and sometimes the grease is eluted and reduced.

[0009] In a refrigeration cycle device using an HFC refrigerant, the difference between the refrigerant pressures at the inlet and the outlet of the electric valve is small, and the force applied to the sliding members is small. Therefore, even if the grease is reduced, the lubricity can be supplemented by the refrigeration oil.

[0010] However, in a refrigeration cycle device using a natural refrigerant, the difference between the refrigerant pressures at the inlet and the outlet of the electric valve is large, and the force applied to the sliding members is large. Therefore, when the grease is reduced, there is a concern that the durability of the sliding members will decrease because the lubricity cannot be supplemented by the refrigeration oil. SUMMARY OF THE INVENTION

[0011] Thus, an object of the present application is to provide an electric valve capable of suppressing a decrease in durability and a refrigeration cycle device using a natural refrigerant and having the electric valve.

[0012] Technical means for solving the technical problem

[0013] To achieve the above object, an electric valve according to an aspect of the present application is an electric valve for a refrigeration cycle device using a natural refrigerant, characterized by including: a valve element; a drive mechanism that drives the valve element; and a housing in which the drive mechanism is disposed on an inner side of the housing, the natural refrigerant being introduced into the inner side of the housing, the drive mechanism including a sliding member to which fluorine grease is applied.

[0014] In the present application, it is preferable that the drive mechanism include a magnetic rotor, a reduction mechanism including a gear, a drive shaft including an external thread, and a bearing member including an internal thread that is screwed with the external thread, the magnetic rotor being connected to the drive shaft via the reduction mechanism, the drive shaft rotating and moving in an axial direction when the magnetic rotor rotates, the valve element moving in the axial direction in conjunction with the movement of the drive shaft, the drive shaft, the bearing member, and the gear being the sliding member.

[0015] In the present application, it is preferable that the drive mechanism include a magnetic rotor, a reduction mechanism including a gear, a drive shaft, and a rotary valve element connected to the drive shaft, the magnetic rotor being connected to the drive shaft via the reduction mechanism, the drive shaft and the rotary valve element rotating when the magnetic rotor rotates, the gear being the sliding member.

[0016] In the present application, it is preferable that the drive mechanism include a magnetic rotor, an external thread member including an external thread, and an internal thread member including an internal thread that is screwed with the external thread, the magnetic rotor being connected to the external thread member, the external thread member rotating and moving in an axial direction with respect to the internal thread member when the magnetic rotor rotates, the valve element moving in the axial direction in conjunction with the movement of the external thread member with respect to the internal thread member, or the magnetic rotor being connected to the internal thread member, the internal thread member rotating and moving in an axial direction with respect to the external thread member when the magnetic rotor rotates, the valve element moving in the axial direction in conjunction with the movement of the internal thread member with respect to the external thread member, the external thread member and the internal thread member being the sliding member.

[0017] In the present application, it is preferable that the fluorine grease include, as a main component, any one of perfluoropolyether, trifluorochloroethylene, and perfluoroalkyl ether.

[0018] In this invention, preferably, the natural refrigerant has carbon dioxide or propane as its main component, and the refrigeration oil flowing with the natural refrigerant has any one of polyol ester, polyalkylene glycol and polyvinyl ether as its main component.

[0019] To achieve the above objectives, another aspect of the present invention relates to a refrigeration cycle device that uses a natural refrigerant, characterized by having an electric valve having: a valve core; a drive mechanism that drives the valve core; and a cover on which the drive mechanism is disposed, the natural refrigerant being introduced into the inside of the cover, the drive mechanism having a sliding member coated with fluorinated grease.

[0020] The effects of the invention

[0021] According to the present invention, the drive mechanism of the electric valve is disposed inside the housing into which the natural refrigerant is introduced, and a fluorinated grease is applied to the sliding parts of the drive mechanism. The fluorinated grease does not react with the main components of the natural refrigerant. Furthermore, the base oil of the fluorinated grease is a fluorinated oil, which is incompatible with, or has very low compatibility with, the refrigeration oil flowing with the natural refrigerant. Therefore, in the electric valve, the dissolution of the fluorinated grease can be suppressed, and the lubricity of the fluorinated grease can be maintained. Thus, the decrease in the durability of the sliding parts of the electric valve can be suppressed. Attached Figure Description

[0022] Figure 1 This is a block diagram of a refrigeration cycle apparatus according to an embodiment of the present invention.

[0023] Figure 2 yes Figure 1 A longitudinal sectional view of the electric valves in the refrigeration cycle unit.

[0024] Figure 3 It's enlarged. Figure 2 A diagram of a portion of an electric valve.

[0025] Figure 4 This indicates experimental results related to the reduction of lubricating grease caused by refrigerant.

[0026] Figure 5 It means Figure 4 The experimental results are shown in a graph. Detailed Implementation

[0027] The following is for reference Figures 1-3 A refrigeration cycle apparatus according to one embodiment of the present invention will be described.

[0028] Figure 1 This is a block diagram of a refrigeration cycle apparatus according to an embodiment of the present invention.Figure 2 yes Figure 1 A longitudinal sectional view of the electric valves in the refrigeration cycle unit. Figure 3 It's enlarged. Figure 2 A diagram of a portion of the electric valve (drive mechanism and its vicinity). In this specification, "up and down" refers to the up and down direction in each diagram.

[0029] The refrigeration cycle device 100 is, for example, an air conditioner. The refrigeration cycle device 100 uses a natural refrigerant.

[0030] In the refrigeration cycle unit 100, natural refrigerant and refrigeration oil circulate. The natural refrigerant is mainly composed of carbon dioxide or propane. The refrigeration oil is, for example, polyalkylene glycol oil (PAG), polyol ester oil (POE), or polyethylene ester oil (PVE).

[0031] like Figure 1 As shown, the refrigeration cycle unit 100 includes a compressor 101, a condenser 102, an electric valve 1, and an evaporator 103 connected in sequence via piping 105. The electric valve 1 is an expansion valve (pressure reducer). The refrigeration cycle unit 100 includes a control device 110. The control device 110 is connected to the electric valve 1. The control device 110 uses the electric valve 1 to control the flow rate of natural refrigerant flowing in the piping 105.

[0032] like Figure 2 , Figure 3 As shown, the electric valve 1 has a valve body 10, a housing 20, a valve core 30, a drive mechanism 40, and a stator unit 70.

[0033] The valve body 10 has a housing 11, a sleeve 14 and a connecting component 16.

[0034] The housing 11 has a cylindrical shape. The housing 11 integrally has a peripheral wall portion 11a and a bottom wall portion 11b. The bottom wall portion 11b is connected to the lower end of the peripheral wall portion 11a. The housing 11 has a valve chamber 12 and a valve port 13. The valve port 13 is disposed in the bottom wall portion 11b and opens into the valve chamber 12. An upward-facing annular plane 11c is provided on the inner peripheral surface of the peripheral wall portion 11a. A transverse hole 11d is provided in the upper part of the peripheral wall portion 11a. A first conduit 18 is joined to the peripheral wall portion 11a. The first conduit 18 is connected to the valve chamber 12. A second conduit 19 is joined to the bottom wall portion 11b. The second conduit 19 is connected to the valve port 13.

[0035] Sleeve 14 has a cylindrical shape. Sleeve 14 integrally comprises a first cylindrical portion 14a, a connecting portion 14b, a second cylindrical portion 14c, and a flange portion 14d. The inner diameter of the second cylindrical portion 14c is larger than the inner diameter of the first cylindrical portion 14a. The connecting portion 14b has an annular plate shape. The inner periphery of the connecting portion 14b is connected to the upper end of the first cylindrical portion 14a, and the outer periphery of the connecting portion 14b is connected to the lower end of the second cylindrical portion 14c. The flange portion 14d has an annular plate shape. The inner periphery of the flange portion 14d is connected to the upper end of the second cylindrical portion 14c. The first cylindrical portion 14a, the connecting portion 14b, and the second cylindrical portion 14c are disposed in valve chamber 12. The flange portion 14d contacts the plane 11c of the housing 11.

[0036] The connecting member 16 has an annular flat plate shape. A peripheral wall portion 11a is disposed on the inner side of the connecting member 16. The inner periphery of the connecting member 16 engages with the peripheral wall portion 11a.

[0037] The outer casing 20 has a cylindrical shape. The lower end of the outer casing 20 is open and the upper end is closed. The lower end of the outer casing 20 engages with the outer periphery of the connecting member 16. The outer casing 20 is a cover.

[0038] The valve core 30 has a main body 31, a valve part 32, a spring support part 33, and a ball support part 34. The main body 31 is cylindrical. The outer diameter of the main body 31 is the same as the inner diameter of the first cylindrical part 14a of the sleeve 14. The valve part 32 is conical with its front end facing downward. The valve part 32 is connected to the lower end of the main body 31. The valve part 32 and the valve port 13 are opposite each other in the vertical direction (axis L direction). The spring support part 33 is annular. The outer diameter of the spring support part 33 is larger than the outer diameter of the main body 31. The spring support part 33 is connected to the upper end of the main body 31. The main body 31, the valve part 32, and the spring support part 33 are formed as one unit.

[0039] The main body 31 is disposed inside the first cylindrical portion 14a and is supported by the first cylindrical portion 14a to be movable in the vertical direction. The main body 31 is disposed inside the valve opening spring 35. The valve opening spring 35 is a compression helical spring. The valve opening spring 35 is disposed between the spring support portion 33 and the connecting portion 14b of the sleeve 14. The valve opening spring 35 presses the valve core 30 upward.

[0040] The ball support portion 34 integrally has a plate portion and a column-shaped protrusion connected to the lower surface of the plate portion. The protrusion engages with a hole provided on the upper end face of the main body portion 31.

[0041] The drive mechanism 40 moves the valve core 30 in the vertical direction. The drive mechanism 40 is located inside the housing 20. The drive mechanism 40 includes a drive shaft 41, a bearing component 45, a magnetic rotor 51, a connecting component 52, a rotor shaft 53, a support component 54, and a planetary gear mechanism 60.

[0042] The drive shaft 41 has a cylindrical portion 42, a flat portion 43, and a ball 44. The cylindrical portion 42 has an external thread 42t. The external thread 42t is disposed on the outer peripheral surface of the cylindrical portion 42. The flat portion 43 extends upward from the upper end surface of the cylindrical portion 42. The cylindrical portion 42 and the flat portion 43 are integrally formed. The ball 44 engages with the lower end surface of the cylindrical portion 42. The drive shaft 41 is connected to the valve core 30. Specifically, the ball 44 of the drive shaft 41 contacts the ball support portion 34 of the valve core 30 in a slidable manner.

[0043] The bearing component 45 has a cylindrical shape. The bearing component 45 is disposed on the inner side of the upper portion of the peripheral wall 11a of the housing 11. The bearing component 45 is fixed to the peripheral wall 11a. The flange portion 14d of the sleeve 14 is held between the lower end face of the bearing component 45 and the plane 11c of the peripheral wall 11a. The bearing component 45 has an internal thread 45t. The internal thread 45t is disposed on the lower part of the inner peripheral surface of the bearing component 45. The external thread 42t of the drive shaft 41 engages with the internal thread 45t. Alternatively, the drive shaft 41 may have an internal thread, and the bearing component 45 may have an external thread that engages with the internal thread of the drive shaft 41.

[0044] The bearing component 45 has a longitudinal hole 45d and an annular groove 45e. The longitudinal hole 45d extends upward from the lower end face of the bearing component 45. The annular groove 45e is disposed on the outer peripheral surface of the bearing component 45 and extends circumferentially. The annular groove 45e is connected to the upper part of the longitudinal hole 45d. The annular groove 45e is connected to the transverse hole 11d of the peripheral wall portion 11a.

[0045] The refrigerant in valve chamber 12 is introduced into the inner side of housing 20 through the gap between sleeve 14 and valve core 30, the inner side of sleeve 14, longitudinal hole 45d, annular groove 45e and transverse hole 11d. Refrigeration oil flowing with the refrigerant is also introduced into the inner side of housing 20.

[0046] The ball support 34, drive shaft 41, and bearing component 45 are preferably made of metals such as stainless steel or brass. Furthermore, the ball support 34, drive shaft 41, and bearing component 45 are preferably subjected to surface hardening treatments such as nitriding.

[0047] The magnetic rotor 51 has a cylindrical shape. The connecting member 52 has a circular plate shape and is connected to the upper end of the magnetic rotor 51. The magnetic rotor 51 is connected to the rotor shaft 53 via the connecting member 52. The support member 54 has a circular plate shape. The support member 54 is disposed above the magnetic rotor 51. The support member 54 supports the upper end of the rotor shaft 53 so that it can rotate.

[0048] The planetary gear mechanism 60 is a speed reduction mechanism that reduces the rotation of the magnetic rotor 51. The planetary gear mechanism 60 connects the magnetic rotor 51 and the drive shaft 41, transmitting the rotation of the magnetic rotor 51 to the drive shaft 41. The planetary gear mechanism 60 is located inside the magnetic rotor 51. The planetary gear mechanism 60 includes a gearbox 61, a fixed gear ring 62, a sun gear 63, multiple planetary gears 64, a planetary gear carrier 65, an output gear 66, and an output shaft 67.

[0049] The gearbox 61 has a cylindrical shape. The gearbox 61 is fixed to the upper part of the peripheral wall 11a of the housing 11. The fixed gear ring 62 is an internal gear. The fixed gear ring 62 is fixed to the upper part of the gearbox 61. The sun gear 63 is coaxially connected to the lower surface of the connecting member 52. The sun gear 63 and the connecting member 52 are integrally formed. A rotor shaft 53 is inserted through the inner side of the sun gear 63. A plurality of planetary gears 64 surround the sun gear 63. The plurality of planetary gears 64 mesh with the fixed gear ring 62 and the sun gear 63. The planetary gear carrier 65 has a plate shape. The planetary gear carrier 65 has a support shaft that supports the plurality of planetary gears 64 for rotation. The output gear 66 is an internal gear with a bottom cylindrical shape. The output gear 66 meshes with the planetary gears 64. Each gear is preferably made of metal such as stainless steel or brass, or engineering plastic such as polytetrafluoroethylene (PTFE).

[0050] The output shaft 67 has a cylindrical shape. The lower part of the output shaft 67 is disposed inside the bearing component 45. The outer peripheral surface of the output shaft 67 is in sliding contact with the inner peripheral surface of the bearing component 45. The output shaft 67 is rotatably supported on the bearing component 45. The upper part of the output shaft 67 is fixed to the bottom of the output gear 66, and the output shaft 67 rotates together with the output gear 66. The output shaft 67 has a support hole for the lower end of the rotor shaft 53. The output shaft 67 supports the lower end of the rotor shaft 53 so that it can rotate. The output shaft 67 is preferably made of a metal such as stainless steel or brass.

[0051] The output shaft 67 has a slit 67a extending in the vertical direction. The slit 67a is disposed at the lower part of the output shaft 67. The width of the slit 67a is the same as the thickness of the flat plate portion 43 of the drive shaft 41. The output shaft 67 is connected to the drive shaft 41. Specifically, the flat plate portion 43 is disposed in the slit 67a in a manner that allows it to move in the vertical direction. When the output shaft 67 rotates, the flat plate portion 43 (drive shaft 41) rotates, and the flat plate portion 43 moves in the vertical direction within the slit 67a.

[0052] The stator unit 70 has a stator 71 and a stator cover 72. The stator 71 has a cylindrical shape. The stator 71 is disposed on the outside of the housing 20. The stator 71 and the magnetic rotor 51 constitute an electric motor. The stator cover 72 is made of plastic and houses the stator 71. The stator unit 70 is fixed to the housing 20.

[0053] The central axis of each of the following components is aligned with axis L: housing 11, valve port 13, sleeve 14, outer shell 20, valve core 30, drive shaft 41, bearing assembly 45, magnetic rotor 51, connecting assembly 52, rotor shaft 53, fixed gear ring 62, sun gear 63, output gear 66, and output shaft 67.

[0054] Next, the operation of electric valve 1 will be explained.

[0055] In the electric valve 1, the stator 71 is energized, causing the magnetic rotor 51 to rotate in one direction. The rotation of the magnetic rotor 51 is transmitted to the drive shaft 41 via the planetary gear mechanism 60. When the drive shaft 41 rotates, it moves downward through a threaded feed action. The drive shaft 41 presses the valve core 30 downward. As the valve core 30 moves downward, the valve portion 32 approaches the valve port 13, and the opening degree of the valve port 13 decreases.

[0056] In the electric valve 1, the stator 71 is energized, causing the magnetic rotor 51 to rotate in the opposite direction. The rotation of the magnetic rotor 51 is transmitted to the drive shaft 41 via the planetary gear mechanism 60. When the drive shaft 41 rotates, it moves upward through the threaded feed action. The valve core 30, pressed by the valve opening spring 35, moves upward, the valve part 32 moves away from the valve port 13, and the opening degree of the valve port 13 increases.

[0057] When the electric valve 1 is activated, components of the drive mechanism 40 slide. Specifically, the external thread 42t of the drive shaft 41 slides against the internal thread 45t of the bearing component 45 (S1), the connecting component 52 slides against the support component 54 (S2), the fixed gear ring 62 slides against the plurality of planetary gears 64 (S3), the sun gear 63 slides against the plurality of planetary gears 64 (S4), the output gear 66 slides against the plurality of planetary gears 64 (S5), the bearing component 45 slides against the output gear 66 (S6), the bearing component 45 slides against the output shaft 67 (S5), the flat plate portion 43 of the drive shaft 41 slides against the inner surface of the slit 67a of the output shaft 67 (S8), and the ball support portion 34 slides against the ball 44 (S9). Figure 2 In the diagram, the sliding parts are represented by symbols S1 to S9.

[0058] The drive shaft 41, bearing assembly 45, connecting assembly 52, support assembly 54, fixed gear ring 62, sun gear 63, multiple planetary gears 64, output gear 66, and output shaft 67 are sliding components. Fluorine grease is applied to the sliding components.

[0059] Fluorinated greases comprise a base oil, a thickener, and a solid lubricant. The base oil is a fluorinated oil, such as an oil whose main components are any of perfluoropolyether (PFPE), trifluorochloroethylene (CTFE), and perfluoroalkyl ether (PFAE). The base oil does not have a chemical structure that reacts with the main components of natural refrigerants (carbon dioxide and propane). The base oil has little or no compatibility with the main components of natural refrigerants and refrigeration oils. In this embodiment, the thickener and solid lubricant are polytetrafluoroethylene (PTFE). PTFE is incompatible with the main components of natural refrigerants and refrigeration oils, or has very little compatibility. Therefore, the fluorinated grease does not dissolve in natural refrigerants and refrigeration oils, or dissolves in very small amounts. Furthermore, as a thickener, bentonite, soap-based (calcium soap, complex calcium soap, sodium soap, aluminum soap, complex aluminum soap, lithium soap, complex lithium soap), silicone, and polyurea can be used instead of PTFE, or they can be mixed with PTFE.

[0060] As described above, the refrigeration cycle device 100 using natural refrigerant has an electric valve 1. The electric valve 1 has a valve core 30, a drive mechanism 40 for driving the valve core 30, and a housing 20 on the inside of the drive mechanism 40. Natural refrigerant and refrigeration oil are introduced into the inside of the housing 20.

[0061] The drive mechanism 40 includes a drive shaft 41, a bearing component 45, a magnetic rotor 51, and a planetary gear mechanism 60. The drive shaft 41 has an external thread 42t. The bearing component 45 has an internal thread 45t for engagement with the external thread 42t. The planetary gear mechanism 60 includes gears (a fixed gear ring 62, a sun gear 63, multiple planetary gears 64, and an output gear 66). The magnetic rotor 51 is connected to the drive shaft 41 via the planetary gear mechanism 60. When the magnetic rotor 51 rotates, the drive shaft 41 rotates and moves vertically. The valve core 30 moves vertically along with the movement of the drive shaft 41. Furthermore, the drive shaft 41, bearing component 45, and gears, which are sliding components, are coated with fluorinated grease.

[0062] Fluorinated grease does not react with the main components of natural refrigerants. Furthermore, the base oil of fluorinated grease is fluorinated oil, which is incompatible or has very low compatibility with the refrigeration oil that flows with the natural refrigerant. Therefore, it can inhibit the dissolution of fluorinated grease in both the natural refrigerant and the refrigeration oil, and maintain the lubricity of the fluorinated grease in sliding parts. Thus, it can prevent a decrease in the durability of the sliding parts of electric valve 1.

[0063] The electric valve 1 can also be structured without a reduction mechanism to slow down the rotation of the magnetic rotor 51. In this structure, for example, the drive mechanism 40 has a magnetic rotor 51, a drive shaft 41, and a bearing component 45. The drive shaft 41 has an external thread 42t. The bearing component 45 has an internal thread 45t for engaging the external thread 42t. The magnetic rotor 51 is directly connected to the drive shaft 41. The valve core 30 is directly connected to the lower end of the drive shaft 41. The rotation of the magnetic rotor 51 is directly transmitted to the drive shaft 41. When the magnetic rotor 51 rotates, the drive shaft 41 rotates and moves vertically relative to the bearing component 45. The drive shaft 41 is an externally threaded component and is the first component. The bearing component 45 is an internally threaded component and is the second component. The valve core 30 moves vertically as the drive shaft 41 moves. Furthermore, the drive shaft 41 and the bearing component 45, which are sliding components, are coated with fluorinated grease. Alternatively, the drive shaft 41 may have an internal thread, and the bearing component 45 may have an external thread that engages with the internal thread of the drive shaft 41.

[0064] Alternatively, the electric valve 1 can replace the valve core 30, which moves in the vertical direction (axis L direction), and instead have a ball valve core (rotary valve core) that rotates about axis L. In this structure, the drive mechanism 40 has a magnetic rotor 51, a planetary gear mechanism 60, a drive shaft 41, and a ball valve core connected to the drive shaft 41. The magnetic rotor 51 is connected to the drive shaft 41 via the planetary gear mechanism 60. When the magnetic rotor 51 rotates, the drive shaft 41 and the ball valve core rotate. The drive shaft 41 does not move in the vertical direction (axial direction). Furthermore, the gears of the planetary gear mechanism 60, which serves as a sliding component, are coated with fluorinated grease.

[0065] These structures also serve the same function as the electric valve 1 mentioned above.

[0066] The inventors conducted tests related to the reduction of lubricating grease caused by refrigerant and refrigeration oil using Examples 1 and 2 and Comparative Examples 1 and 2 of the present invention.

[0067] (Example 1)

[0068] Prepare an assembly consisting of a magnetic rotor 51, a connecting component 52, a rotor shaft 53, and a planetary gear mechanism 60. Apply a specified amount of fluorinated grease to the sliding parts included in the assembly, and after measuring the weight of the assembly (initial weight), assemble it onto the electric valve 1. The fluorinated grease uses a grease containing PFAE (base oil) and PTFE (thickener and solid lubricant) as its main components.

[0069] (Example 2)

[0070] An assembly consisting of a magnetic rotor 51, connecting component 52, rotor shaft 53, and planetary gear mechanism 60 was prepared. A prescribed amount of fluorinated grease was applied to the sliding parts of the assembly, and the weight of the assembly (initial weight) was measured. Then, the assembly was immersed in refrigeration oil (temperature 120 degrees Celsius) for 96 hours before being assembled to the electric valve 1. The same fluorinated grease as in Example 1 was used. The refrigeration oil used was a polyvinyl ether-based refrigeration oil used in refrigeration cycle systems employing HFC refrigerants. Example 2 simulated the effect of the refrigeration oil.

[0071] (Comparative Example 1)

[0072] Prepare an assembly consisting of a magnetic rotor 51, a connecting component 52, a rotor shaft 53, and a planetary gear mechanism 60. Apply a specified amount of mineral oil grease to the sliding parts included in the assembly, and after measuring the weight of the assembly (initial weight), assemble it onto the electric valve 1. The mineral oil grease uses a grease containing mineral oil (base oil), bentonite (thickener), and molybdenum disulfide (solid lubricant) as its main components.

[0073] (Comparative Example 2)

[0074] An assembly consisting of a magnetic rotor 51, a connecting component 52, a rotor shaft 53, and a planetary gear mechanism 60 was prepared. A predetermined amount of mineral oil grease was applied to the sliding parts of the assembly, and the weight of the assembly (initial weight) was measured. Then, the assembly was immersed in refrigeration oil (temperature 120 degrees Celsius) for 96 hours and assembled onto the electric valve 1. The same mineral oil grease as in Comparative Example 1 was used. The same refrigeration oil as in Example 2 was used. Comparative Example 2 simulated the effect of the refrigeration oil.

[0075] (test)

[0076] A refrigerant supply device is connected to one conduit of the electric valve 1, and a refrigerant recovery device is connected to the other conduit. A filling and recovery operation is performed where liquid refrigerant (excluding refrigeration oil) is filled into the valve chamber 12 and housing 20 of the electric valve 1 through the refrigerant supply device, and the refrigerant is recovered by the refrigerant recovery device, thus emptying the valve chamber 12 and housing 20. In Example 1 and Comparative Example 1, when the grease is compatible with the refrigerant, the grease dissolves in the recovered refrigerant. In Example 2 and Comparative Example 2, when the grease is compatible with the refrigeration oil, the grease dissolves when immersed in the refrigeration oil and flows out from the applied area. Even if refrigeration oil or grease dissolved in refrigeration oil remains in the electric valve 1, both the grease and refrigeration oil are recovered along with the refrigerant because the refrigeration oil dissolves in the refrigerant. After a predetermined number of filling and recovery operations, the assembly is removed from the electric valve 1, and the weight of the assembly is measured. The remaining grease (%) is calculated based on the initial weight and the measured weight. The refrigerant used was R410A (HFC refrigerant). The refrigeration oil used in the test was compatible with R410A. The test results of Examples 1 and 2 and Comparative Examples 1 and 2 are as follows: Figure 4 , Figure 5 As shown. Figure 4 This is a table that indicates the number of filling and recycling operations and the remaining amount of grease. Figure 5 It is a graph showing the relationship between the number of filling and recycling operations and the remaining amount of grease.

[0077] When Comparative Examples 1 and 2 were repeatedly filled and recycled 20 times, the grease in Comparative Example 1 hardly decreased, but the grease in Comparative Example 2 decreased significantly. This shows that mineral oil grease does not react with HFC refrigerant, but it is compatible with refrigeration oil. When the refrigeration oil flows with the refrigerant, the mineral oil grease dissolves out.

[0078] When the filling operation was repeatedly performed on Examples 1 and 2, the amount of grease in Examples 1 and 2 gradually decreased with the increase of the number of operations. In Examples 1 and 2, the grease decreased similarly, and even when simulating the effect of refrigeration oil, the change in the remaining grease amount was not different. This indicates that fluorinated grease is not compatible with refrigeration oil. It is speculated that the decrease in fluorinated grease is due to the reaction between the base oil of the fluorinated grease and the HFC refrigerant. On the other hand, the base oil of fluorinated grease does not have a chemical structure that reacts with the main components of natural refrigerants. Therefore, it is believed that fluorinated grease will not dissolve in natural refrigerants and refrigeration oil. These experimental results confirm the effectiveness of the present invention.

[0079] In this specification, the terms "cylinder," "cylindrical," etc., are also used for parts or components that substantially have the shape described by that term. For example, "cylindrical-shaped component" includes both cylindrical-shaped components and substantially cylindrical-shaped components. Furthermore, in this specification, the term "same" sometimes includes cases of strict sameness and cases of substantial sameness.

[0080] The embodiments of the present invention have been described above, but the present invention is not limited to these embodiments. Structures obtained by adding, deleting, or modifying constituent elements, or by appropriately combining features of the embodiments, relative to the embodiments described above, are also included within the scope of the present invention, as long as they do not depart from the spirit of the present invention.

[0081] Symbol Explanation

[0082] 1…Electric valve, 10…Valve body, 11…Housing, 11a…Peripheral wall, 11b…Bottom wall, 11c…Flat surface, 11d…Horizontal hole, 12…Valve chamber, 13…Valve port, 14…Sleeve, 14a…First cylindrical part, 14b…Connecting part, 14c…Second cylindrical part, 14d…Flange, 16…Connecting component, 18…First conduit, 19…Second conduit, 20…Outer shell, 30…Valve core, 31…Main body, 32…Valve part, 33…Spring support, 34…Ball support, 35…Opening spring, 40…Drive mechanism, 41…Drive shaft, 42…Cylindrical part, 42t…External thread, 43…Plate part, 44…Ball, 4 5…Bearing component, 45d…Longitudinal hole, 45e…Annular groove, 45t…Internal thread, 51…Magnetic rotor, 52…Connecting component, 53…Rotor shaft, 54…Support component, 60…Planetary gear mechanism, 61…Gearbox, 62…Fixed gear ring, 63…Sun gear, 64…Planetary gear, 65…Planetary gear carrier, 66…Output gear, 67…Output shaft, 67a…Slit, 70…Stator unit, 71…Stator, 72…Stator cover, 100…Refrigeration cycle device, 101…Compressor, 102…Condenser, 103…Evaporator, 105…Piping, 110…Control device, L…Axis, S1~S9…Sliding parts.

Claims

1. An electric valve for use in a refrigeration cycle device using a natural refrigerant, characterized in that, It comprises: a valve core; a drive mechanism that drives the valve core; and a cover on the inside of the cover, wherein the drive mechanism is disposed. The natural refrigerant is introduced into the inside of the cover. The drive mechanism has a sliding component. The sliding component is coated with fluorinated grease.

2. The electric valve according to claim 1, characterized in that, The drive mechanism includes: a magnetic rotor; a reduction mechanism having gears; a drive shaft having external threads; and a bearing component having internal threads that engage with the external threads. The magnetic rotor is connected to the drive shaft via the reduction mechanism. When the magnetic rotor rotates, the drive shaft rotates and moves axially. The valve core moves along the axial direction as the drive shaft moves. The drive shaft, the bearing component, and the gear are the sliding components.

3. The electric valve according to claim 1, characterized in that, The drive mechanism includes: a magnetic rotor; a reduction mechanism having gears; a drive shaft; and a rotary valve core connected to the drive shaft. The magnetic rotor is connected to the drive shaft via the reduction mechanism. When the magnetic rotor rotates, the drive shaft and the rotary valve core rotate. The gear is the sliding component.

4. The electric valve according to claim 1, characterized in that, The drive mechanism includes: a magnetic rotor; an external threaded component having an external thread; and an internal threaded component having an internal thread that engages with the external thread. The magnetic rotor is connected to the external threaded component. When the magnetic rotor rotates, the external threaded component rotates and moves axially relative to the internal threaded component. Accompanying this movement, the valve core moves along the axial direction. Alternatively, the magnetic rotor is connected to the internal threaded component. When the magnetic rotor rotates, the internal threaded component rotates and moves axially relative to the external threaded component. Accompanying this movement, the valve core moves along the axial direction. The external threaded component and the internal threaded component are the sliding components.

5. The electric valve according to claim 1, characterized in that, The base oil of the fluorinated grease is composed primarily of any one of perfluoropolyether, trifluorochloroethylene, and perfluoroalkyl ether.

6. The electric valve according to claim 1, characterized in that, The natural refrigerant is mainly composed of carbon dioxide or propane. The refrigeration oil flowing with the natural refrigerant has one of the following as its main components: polyol ester, polyalkylene glycol, and polyvinyl ether.

7. A refrigeration cycle device using a natural refrigerant, characterized in that, The device has an electric valve comprising: a valve core; a drive mechanism that drives the valve core; and a cover on the inside of the cover, wherein the drive mechanism is disposed. The natural refrigerant is introduced into the inside of the cover. The drive mechanism has a sliding component. The sliding component is coated with fluorinated grease.

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