Motorized valve

Abstract

The present application provides an electric valve capable of inhibiting invasion of foreign matter into an inner space of a casing and capable of inhibiting generation of malfunction, abnormal sound caused by a pressure difference between a refrigerant pressure of a valve chamber and a refrigerant pressure of the inner space of the casing. The electric valve (1) has a refrigerant passage (K) connecting the valve chamber (13) and an inner space (30e) of the casing (30). The refrigerant passage (K) has an inner space (20e) of a retainer (20), a first annular groove (28) formed between the retainer (20) and a valve core support member (25), a first longitudinal hole (29) formed in the valve core support member (25) and connecting the valve chamber (13) and the first annular groove (28), and a gap (24) formed between the retainer (20) and the valve core support member (25) and connecting an inner periphery of the first annular groove (28) and the inner space (20e) of the retainer (20).

Description

Technical Field

[0001] This invention relates to an electric valve. Background Technology

[0002] Patent Document 1 discloses a conventional electric valve. The electric valve of Patent Document 1 includes: a valve body, a valve core, a housing, a rotor, a reduction gear, and a threaded mechanism. The valve body has a valve chamber and a valve seat. The valve core is located inside the valve chamber, directly opposite the valve seat. A rotor is disposed inside the housing. The rotation of the rotor is reduced by the reduction gear and converted into linear motion by the threaded mechanism, which is then transmitted to the valve core. The electric valve has a refrigerant passage connecting the valve chamber to the inner space of the housing. A foreign matter intrusion prevention component is disposed in the refrigerant passage. The foreign matter intrusion prevention component is a filter such as a porous material or a metal mesh. The foreign matter intrusion prevention component captures foreign matter contained in the refrigerant, thereby preventing foreign matter from intruding from the valve chamber into the inner space of the housing.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2008-275120

[0006] The technical problem that the invention aims to solve

[0007] However, in the aforementioned electric valve, the foreign object intrusion prevention component hinders the rapid flow of refrigerant in the refrigerant passage, and a relatively long time is required for the change in refrigerant pressure in the valve chamber to be transmitted to the refrigerant in the inner space of the housing. Therefore, when the refrigerant pressure in the valve chamber changes drastically, the pressure difference between the refrigerant pressure in the valve chamber and the refrigerant pressure in the inner space of the housing increases. Consequently, when the valve core is actuated, malfunctions and abnormal noises may occur in the reduction mechanism and threaded mechanism. Summary of the Invention

[0008] Therefore, the object of the present invention is to provide an electric valve that can suppress the intrusion of foreign objects into the inner space of the housing and suppress the generation of malfunctions and abnormal noises caused by the pressure difference between the refrigerant pressure in the valve chamber and the refrigerant pressure in the inner space of the housing.

[0009] Technical means for solving technical problems

[0010] To achieve the above objectives, an electric valve according to one aspect of the present invention comprises: a valve body having a valve chamber and a valve port; a valve core configured to face the valve port; a cylindrical retainer mounted on the valve body; a valve core support member having a surface contacting the retainer and a surface facing the valve chamber; a cylindrical housing engaging with the retainer; and a drive mechanism disposed inside the housing and driving the valve core, wherein the electric valve has a refrigerant passage connecting the valve chamber to an inner space of the housing, the refrigerant passage comprising: an inner space of the retainer; a first annular passage formed between the retainer and the valve core support member; a first longitudinal passage formed in the valve core support member and connecting the valve chamber to the first annular passage; and a gap formed between the retainer and the valve core support member and connecting the inner periphery of the first annular passage to the inner space of the retainer.

[0011] According to the present invention, the electric valve has a refrigerant passage connecting the valve chamber to the inner space of the housing. The refrigerant passage includes: an inner space of the retainer; a first annular passage formed between the retainer and the valve core support member; a first longitudinal passage formed in the valve core support member and connecting the valve chamber to the first annular passage; and a gap formed between the retainer and the valve core support member, connecting the inner periphery of the first annular passage to the inner space of the retainer. Thus, refrigerant flows from the valve chamber into the first annular passage via the first longitudinal passage, flowing circumferentially within the first annular passage. In the first annular passage, foreign matter contained in the refrigerant moves towards the outer periphery due to centrifugal force. Refrigerant flows from the inner edge of the first annular passage into the inner space of the retainer via the gap between the retainer and the valve core support member. At this time, foreign matter contained in the refrigerant is retained on the outer periphery of the first annular passage, while refrigerant with less foreign matter on the inner periphery of the first annular passage flows into the inner space of the retainer via the gap. Therefore, by not installing filters or similar equipment in the refrigerant passage of an electric valve, it is possible to prevent foreign objects from entering the inner space of the housing, and to rapidly transmit changes in refrigerant pressure in the valve chamber to the refrigerant in the inner space of the housing. Thus, the electric valve can suppress malfunctions and abnormal noises caused by the pressure difference between the refrigerant pressure in the valve chamber and the refrigerant pressure in the inner space of the housing.

[0012] In this invention, preferably, the drive mechanism has: a cylindrical guide member disposed inside the retainer, and an internal thread formed on the inner circumferential surface of the guide member; and a drive shaft with an external thread forming on the outer circumferential surface of the drive shaft that engages with the internal thread. The refrigerant passage also has: a second annular passage formed between the retainer and the guide member; a second longitudinal passage formed on the guide member and connecting the inner space of the retainer to the second annular passage; and a transverse passage formed on the retainer and connecting the second annular passage to the inner space of the housing. Thus, the refrigerant passage has a complex passage shape comprising two passage portions ([1] the first annular passage and the first longitudinal passage, [2] the second annular passage and the second longitudinal passage) composed of an annular passage and a longitudinal passage. Furthermore, the foreign matter contained in the refrigerant has a higher specific gravity than the refrigerant and is less likely to change its flow direction compared to the refrigerant. Therefore, in the refrigerant passage, foreign objects can be retained at the location where the refrigerant flow direction changes, which can further inhibit the intrusion of foreign objects into the inner space of the casing.

[0013] In this invention, it is preferable that the size of the gap is smaller than the clearance of the drive mechanism. Therefore, the passage of foreign objects that might affect the operation of the drive mechanism is restricted within the gap, thus suppressing malfunctions of the electric valve caused by foreign objects.

[0014] The effects of the invention

[0015] According to the present invention, it is possible to suppress the intrusion of foreign objects into the inner space of the housing, and to suppress the generation of malfunctions and abnormal sounds caused by the pressure difference between the refrigerant pressure in the valve chamber and the refrigerant pressure in the inner space of the housing. Attached Figure Description

[0016] Figure 1 This is a longitudinal sectional view of an electric valve according to an embodiment of the present invention.

[0017] Figure 2 It's enlarged. Figure 1 A cross-sectional view of a portion of an electric valve.

[0018] Figure 3 yes Figure 1 A top view of the valve core support component of the electric valve.

[0019] Figure 4 It is along Figure 2 A cross-sectional view along line IV-IV.

[0020] Symbol Explanation

[0021] 1…Electric valve, 10…Valve body, 10a…Left side, 10b…Right side, 10c…Top, 13…Valve chamber, 14…Valve port, 17…First passage, 18…Second passage, 19…Mounting hole, 19a…Bottom surface, 20…Cage, 20b…Lower end face, 20d…Inner circumferential surface, 20e…Inner space, 21…Lower part, 22…Upper part, 23…Horizontal hole, 24…Gap, 25…Valve core support component, 25e…Valve core support hole, 26…Large diameter part, 26a…Upper end face, 26b…Lower end face, 26f…Annular plane, 27…Small diameter part, 27c…Outer circumferential surface, 28…First annular groove, 28d…Inner side surface, 29…First longitudinal hole, 30…Housing, 30e…Inner space, 35…Connecting component, 40…Driver Mechanism, 41…Magnetic rotor, 42…Connecting component, 43…Rotor shaft, 50…Planetary gear mechanism, 51…Gear housing, 52…Fixed gear ring, 53…Sun gear, 54…Planetary gear, 55…Gear carrier, 55a…Support shaft, 56…Output gear, 57…Output shaft, 57a…Slit, 60…Guide component, 60b…Lower end face, 60f…Internal thread, 61…Second annular groove, 62…Second longitudinal hole, 65…Drive shaft, 66…Cylindrical part, 66f…External thread, 67…Plate part, 68…Ball, 70…Valve core, 71…Rod, 72…Valve part, 73…Spring support part, 73a…Flange part, 74…Ball receiving part, 75…Valve opening spring, 80…Stator unit, 90…Stator, 95…Cover, K…Refrigerant passage Detailed Implementation

[0022] The following is for reference Figures 1 to 4 An embodiment of the electric valve of the present invention will be described. The electric valve 1 of this embodiment is used, for example, in a refrigeration cycle for adjusting the refrigerant flow rate.

[0023] Figure 1 This is a longitudinal sectional view of an electric valve according to an embodiment of the present invention. Figure 2 It's enlarged. Figure 1 A cross-sectional view of a portion of an electric valve. Figure 3 yes Figure 1 A top view of the valve core support component of the electric valve. Figure 4 It is along Figure 2 A cross-sectional view along line IV-IV.

[0024] like Figure 1 As shown, the electric valve 1 of this embodiment includes: valve body 10, retainer 20, valve core support component 25, housing 30, drive mechanism 40, valve core 70, and stator unit 80.

[0025] The valve body 10 has a cuboid shape. The valve body 10 has a valve chamber 13 and a valve port 14 connected to the valve chamber 13. The valve body 10 has a first passage 17 and a second passage 18. One end of the first passage 17 is connected to the valve chamber 13, and the other end of the first passage 17 opens on the left side 10a of the valve body 10. One end of the second passage 18 is connected to the valve chamber 13 via the valve port 14, and the other end of the second passage 18 opens on the right side 10b of the valve body 10. The valve body 10 has a mounting hole 19. The mounting hole 19 opens on the upper surface 10c of the valve body 10. An internal thread is formed on the inner circumferential surface of the mounting hole 19. The valve chamber 13 opens on the bottom surface 19a of the mounting hole 19.

[0026] The retainer 20 has a cylindrical shape. An external thread is formed on the outer circumferential surface of the lower portion 21 of the retainer 20. The external thread of the retainer 20 engages with the internal thread of the mounting hole 19 of the valve body 10. The retainer 20 is mounted to the valve body 10 via a threaded structure. A radially penetrating transverse hole 23 is formed on the upper portion 22 of the retainer 20.

[0027] The valve core support component 25 integrally has a large diameter portion 26 and a small diameter portion 27.

[0028] The large-diameter portion 26 has a cylindrical shape. The upper end face 26a of the large-diameter portion 26 contacts the lower end face 20b of the retainer 20. A first annular groove 28 is formed on the upper end face 26a of the large-diameter portion 26. The first annular groove 28 is coaxially arranged with the large-diameter portion 26. The first annular groove 28 is a first annular passage formed between the retainer 20 and the large-diameter portion 26. The lower end face 26b of the large-diameter portion 26 faces the valve chamber 13. The large-diameter portion 26 has a first longitudinal hole 29 extending upward from the lower end face 26b. The first longitudinal hole 29 is arranged parallel to the axial direction of the large-diameter portion 26. The upper end of the first longitudinal hole 29 connects to the first annular groove 28. The lower end of the first longitudinal hole 29 connects to the valve chamber 13. The first longitudinal hole 29 is a first longitudinal passage formed in the large-diameter portion 26 and connects the valve chamber 13 to the first annular groove 28. A downward-facing annular plane 26f is formed on the outer peripheral surface of the large-diameter portion 26. The large-diameter portion 26 is pressed into the valve chamber 13 from the mounting hole 19 side. The annular plane 26f abuts against the bottom surface 19a of the mounting hole 19. The large-diameter portion 26 is disposed inside the mounting hole 19 between the valve body 10 and the retainer 20.

[0029] The small-diameter portion 27 has a cylindrical shape. The small-diameter portion 27 is coaxially connected to the upper end face 26a of the large-diameter portion 26. The diameter of the outer peripheral surface 27c of the small-diameter portion 27 is the same as the diameter of the inner side surface 28d of the first annular groove 28. The diameter of the inner peripheral surface of the small-diameter portion 27 is the same as the diameter of the inner peripheral surface of the large-diameter portion 26. The inner peripheral surfaces of the large-diameter portion 26 and the small-diameter portion 27 form a valve core support hole 25e. A valve core 70 is disposed inside the valve core support hole 25e. The valve core support member 25 supports the valve core 70 so that it can move in the vertical direction. The small-diameter portion 27 is disposed inside the retainer 20. The diameter of the outer peripheral surface 27c of the small-diameter portion 27 is slightly smaller than the diameter of the inner peripheral surface 20d of the retainer 20. The outer peripheral surface 27c of the small-diameter portion 27 and the inner peripheral surface 20d of the retainer 20 form an annular gap 24. The gap 24 connects the inner periphery of the first annular groove 28 to the inner space 20e of the retainer 20. In addition, the gap 24 only needs to connect the inner periphery of the first annular groove 28 to the inner space 20e of the retainer 20, and the diameter of the outer peripheral surface 27c of the small diameter portion 27 can also be the same as the diameter of the inner side surface 28d of the first annular groove 28.

[0030] The housing 30 has a cylindrical shape with a closed upper end and an open lower end. The lower end of the housing 30 engages with the outer periphery of a ring-shaped engaging member 35. The upper part of a retainer 20 is disposed inside the engaging member 35. The inner periphery of the engaging member 35 engages with the retainer 20. The housing 30 is indirectly engaged with the retainer 20 via the engaging member 35. The housing 30 may also be directly engaged with the retainer 20.

[0031] The drive mechanism 40 moves the valve core 70 in the vertical direction. The drive mechanism 40 includes: a magnetic rotor 41, a planetary gear mechanism 50, a guide member 60, a drive shaft 65, and a ball 68.

[0032] The magnet rotor 41 has a cylindrical shape. On the outer circumferential surface of the magnet rotor 41, the N pole and S pole are alternately arranged in the circumferential direction. The outer diameter of the magnet rotor 41 is smaller than the inner diameter of the housing 30. The magnet rotor 41 is arranged inside the housing 30 to be rotatable. A circular plate-shaped connecting member 42 engages with the upper end of the magnet rotor 41. The connecting member 42 closes the upper end of the magnet rotor 41. The rotor shaft 43 passes through the center of the connecting member 42. The magnet rotor 41 is connected to the rotor shaft 43 via the connecting member 42.

[0033] A planetary gear mechanism 50 is disposed inside the magnet rotor 41. The planetary gear mechanism 50 includes: a gear housing 51, a fixed gear ring 52, a sun gear 53, multiple planetary gears 54, a gear carrier 55, an output gear 56, and an output shaft 57. The gear housing 51 has a cylindrical shape. The gear housing 51 is coaxially engaged with the upper end of the cage 20. The fixed gear ring 52 is an internal gear. The fixed gear ring 52 is fixed to the upper end of the gear housing 51. The sun gear 53 is configured to be coaxial with the connecting member 42. The sun gear 53 and the connecting member 42 are integrated. The rotor shaft 43 passes through the sun gear 53. The sun gear 53 rotates together with the magnet rotor 41 and the connecting member 42. Multiple planetary gears 54 are disposed between the fixed gear ring 52 and the sun gear 53. The gear carrier 55 has a circular plate shape. The rotor shaft 43 passes through the center of the gear carrier 55. The gear carrier 55 is rotatable about the rotor shaft 43. The gear carrier 55 has multiple support shafts 55a. These support shafts 55a support multiple planetary gears 54 for free rotation. The output gear 56 has a bottomed cylindrical shape. The output gear 56 is an internal gear. Multiple planetary gears 54 are arranged between the output gear 56 and the sun gear 53. The output shaft 57 has a cylindrical shape. The upper part of the output shaft 57 is fixed to a hole formed in the bottom of the output gear 56. A slit 57a extending in the vertical direction is formed in the lower part of the output shaft 57. The rotation of the sun gear 53 is transmitted to the output shaft 57 by the fixed gear ring 52, the multiple planetary gears 54, the gear carrier 55, and the output gear 56, which reduces the speed.

[0034] The guide member 60 has a cylindrical shape. The guide member 60 fits inside the upper portion 22 of the retainer 20. An internal thread 60f is formed on the lower part of the inner circumferential surface of the guide member 60. An output shaft 57 is disposed inside the guide member 60. The guide member 60 supports the output shaft 57 for rotation. A second annular groove 61 is formed on the outer circumferential surface of the guide member 60. The second annular groove 61 is configured to be coaxial with the guide member 60. The second annular groove 61 connects to the transverse hole 23 of the retainer 20. The second annular groove 61 is a second annular passage formed between the retainer 20 and the guide member 60. The transverse hole 23 is a transverse passage formed in the retainer 20 and connects the second annular groove 61 to the inner space 30e of the housing 30. The lower end face 60b of the guide member 60 faces the inner space 20e of the retainer 20. The guide member 60 has a second longitudinal hole 62 extending upward from the lower end face 60b. The second longitudinal hole 62 is configured to be parallel to the axial direction of the guide member 60. The upper end of the second longitudinal hole 62 is connected to the second annular groove 61. The lower end of the second longitudinal hole 62 is connected to the inner space 20e of the retainer 20. The second longitudinal hole 62 is positioned 180 degrees offset from the transverse hole 23 about the axis of the retainer 20. The second longitudinal hole 62 is a second longitudinal passage formed in the guide member 60, connecting the inner space 20e of the retainer 20 to the second annular groove 61.

[0035] The drive shaft 65 has a cylindrical portion 66 and a flat portion 67. The flat portion 67 is connected to the upper end of the cylindrical portion 66. The cylindrical portion 66 and the flat portion 67 are integrally formed. An external thread 66f is formed on the outer peripheral surface of the cylindrical portion 66. The external thread 66f of the cylindrical portion 66 engages with the internal thread 60f of the guide member 60. The flat portion 67 is configured in the slit 57a of the output shaft 57 to be movable in the vertical direction. The drive shaft 65 rotates via the output shaft 57 and moves in the vertical direction via threaded feed. A ball 68 is disposed between the drive shaft 65 and the ball receiving portion 74 of the valve core 70.

[0036] The clearance 24 is larger than the clearance of the planetary gear mechanism 50, but smaller than the clearance of the internal thread 60f of the guide member 60 and the external thread 66f of the drive shaft 65.

[0037] The valve core 70 includes a rod 71, a valve portion 72, a spring support portion 73, and a ball receiving portion 74. The rod 71 is cylindrical. The rod 71 is disposed in a valve core support hole 25e of the valve core support member 25. The rod 71 is supported by the valve core support member 25 and is movable in the vertical direction. The valve portion 72 is connected to the lower end of the rod 71. The valve portion 72 is annular. The valve portion 72 protrudes radially outward from the outer peripheral surface of the rod 71. The valve portion 72 is positioned directly opposite the valve port 14 in the vertical direction. The spring support portion 73 is cylindrical. The spring support portion 73 engages with the upper end of the rod 71. The spring support portion 73 has a flange portion 73a protruding radially outward. The ball receiving portion 74 has a circular flat plate portion and a protrusion connected to the lower surface of the flat plate portion. The flat plate portion of the ball receiving portion 74 contacts a ball 68, and the protrusion engages with a hole formed in the spring support portion 73. An opening spring 75 is disposed between the flange portion 73a of the spring support portion 73 and the small-diameter portion 27 of the valve core support member 25. The opening spring 75 is a compression helical spring. The opening spring 75 pushes the valve core 70 (flange portion 73a) upward. The valve core 70 continuously changes the opening area of ​​the valve port 14 by moving the valve portion 72 forward and backward relative to the valve port 14. The valve core 70 can close the valve port 14 (i.e., it can also make the opening area 0).

[0038] The stator unit 80 has a stator 90 and a cover 95. The stator 90 has a cylindrical shape. A housing 30 is disposed inside the stator 90. The cover 95 houses the stator 90. The stator unit 80 and the magnet rotor 41 together constitute a stepper motor.

[0039] The electric valve 1 has a refrigerant passage K that connects the valve chamber 13 to the inner space 30e of the housing 30. The refrigerant passage K has a first longitudinal hole 29, a first annular groove 28, a gap 24, the inner space 20e of the retainer 20, a second longitudinal hole 62, a second annular groove 61 and a transverse hole 23 connected sequentially from the valve chamber 13 side.

[0040] In the electric valve 1, the valve port 14, the cage 20, the valve core support component 25, the housing 30, the magnet rotor 41, the connecting component 42, the rotor shaft 43, the output shaft 57, the guide component 60, the drive shaft 65, the valve core 70, and the stator 90 all have the same central axis.

[0041] Next, the operation of electric valve 1 will be explained.

[0042] In the electric valve 1, current flows through the coils of the stator 90, causing the magnet rotor 41 to rotate in one direction. The rotation of the magnet rotor 41 is transmitted to the drive shaft 65 via the planetary gear mechanism 50. Through the threaded feed action between the drive shaft 65 and the guide member 60, the drive shaft 65 moves downward. The valve core 70 is pushed downward by the drive shaft 65, thereby reducing the opening area of ​​the valve port 14.

[0043] In the electric valve 1, current flows through the coils of the stator 90, causing the magnet rotor 41 to rotate in the opposite direction. The rotation of the magnet rotor 41 is transmitted to the drive shaft 65 via the planetary gear mechanism 50. The drive shaft 65 moves upward through the threaded feed action between the drive shaft 65 and the guide member 60. The valve core 70 is pushed upward by the valve opening spring 75, thereby increasing the opening area of ​​the valve port 14.

[0044] The electric valve 1 includes: a valve body 10 having a valve chamber 13 and a valve port 14; a valve core 70 configured to face the valve port 14; a cylindrical retainer 20 mounted on the valve body 10; a valve core support member 25 having an upper end face 26a contacting the retainer 20 and a lower end face 26b facing the valve chamber 13; a cylindrical housing 30 engaging with the retainer 20; and a drive mechanism 40 disposed inside the housing 30 and driving the valve core 70. The electric valve 1 has a refrigerant passage K connecting the valve chamber 13 to the inner space 30e of the housing 30. The refrigerant passage K has: an inner space 20e of the retainer 20; a first annular groove 28 formed between the retainer 20 and the valve core support member 25; a first longitudinal hole 29 formed in the valve core support member 25 and connecting the valve chamber 13 to the first annular groove 28; and a gap 24 formed between the retainer 20 and the valve core support member 25 and connecting the inner periphery of the first annular groove 28 to the inner space 20e of the retainer 20.

[0045] Therefore, the refrigerant introduced into the valve chamber 13 flows from the valve chamber 13 into the first annular groove 28 through the first longitudinal hole 29, and flows circumferentially in the first annular groove 28. In the first annular groove 28, foreign matter contained in the refrigerant moves towards the outer periphery due to centrifugal force. The refrigerant flows from the inner edge of the first annular groove 28 into the inner space 20e of the retainer 20 through the gap 24. At this time, foreign matter contained in the refrigerant is retained on the outer periphery of the first annular groove 28, while refrigerant with less foreign matter on the inner periphery of the first annular groove 28 flows into the inner space 20e of the retainer 20 through the gap 24. Therefore, in the electric valve 1, even without installing a filter or the like in the refrigerant passage K, it is possible to suppress the intrusion of foreign matter into the inner space 30e of the housing 30, and to quickly transmit changes in the refrigerant pressure in the valve chamber 13 to the refrigerant in the inner space 30e of the housing 30. Therefore, the electric valve 1 can suppress malfunctions and abnormal noises caused by the pressure difference between the refrigerant pressure in the valve chamber 13 and the refrigerant pressure in the inner space 30e of the housing 30.

[0046] In addition, the drive mechanism 40 has: a cylindrical guide member 60 disposed inside the retainer 20 and having an internal thread 60f formed on its inner circumferential surface; and a drive shaft 65 having an external thread 66f formed on its outer circumferential surface that engages with the internal thread 60f. The refrigerant passage K also has: a second annular groove 61 formed between the retainer 20 and the guide member 60; a second longitudinal hole 62 formed in the guide member 60 and connecting the inner space 20e of the retainer 20 to the second annular groove 61; and a transverse hole 23 formed in the retainer 20 and connecting the second annular groove 61 to the inner space 30e of the housing 30. Thus, the refrigerant passage K has a complex passage shape comprising two passage portions ([1] the first annular groove 28 and the first longitudinal hole 29, [2] the second annular groove 61 and the second longitudinal hole 62) composed of annular passages and longitudinal passages. Furthermore, the foreign matter contained in the refrigerant has a higher specific gravity than the refrigerant and is less likely to change its flow direction compared to the refrigerant. Therefore, in the refrigerant passage K, the foreign matter can be retained at the location where the flow direction of the refrigerant changes, which can further suppress the intrusion of foreign matter into the inner space 30e of the casing 30.

[0047] Furthermore, the clearance of gap 24 is smaller than the clearance of drive mechanism 40 (planetary gear mechanism 50, guide member 60 and threaded mechanism of drive shaft 65). Thus, the passage of foreign objects that may affect the operation of drive mechanism 40 is restricted in gap 24, and malfunction of electric valve 1 caused by foreign objects can be suppressed.

[0048] The electric valve 1 described above transmits the rotation of the magnet rotor 41 to the drive shaft 65 by reducing the speed through the planetary gear mechanism 50. The electric valve 1 can also be a direct-acting electric valve with a structure that directly transmits the rotation of the magnet rotor 41 to the drive shaft 65.

[0049] The embodiments of the present invention have been described above, but the present invention is not limited to the structure of the embodiments. Examples of appropriate additions, deletions, design changes, or appropriate combinations of features of the embodiments by those skilled in the art, as long as they do not violate the spirit of the present invention, are included within the scope of the present invention.

Claims

1. An electric valve comprising: a valve body having a valve chamber and a valve port; a valve core configured to face the valve port; and a cylindrical retainer mounted on the valve body; The electric valve comprises: a valve core support member having a surface contacting the cage and a surface facing the valve chamber; a cylindrical housing engaging with the cage; and a drive mechanism disposed inside the housing and driving the valve core. The electric valve has a refrigerant passage connecting the valve chamber to the inner space of the housing. The refrigerant passage has the following characteristics: The inner space of the cage; A first annular passage is formed between the retainer and the valve core support member; A first longitudinal passage is formed in the valve core support component and connects the valve chamber to the first annular passage. as well as A gap through which refrigerant can flow is formed between the cage and the valve core support member, and connects the inner periphery of the first annular passage to the inner space of the cage.

2. The electric valve according to claim 1, characterized in that, The drive mechanism has: A cylindrical guide member disposed inside the cage, and having an internal thread formed on its inner circumferential surface; and The drive shaft has an external thread formed on its outer circumferential surface that engages with the internal thread. The refrigerant passage also has: A second annular passage is formed between the retainer and the guide member; The second longitudinal passage is formed in the guide member and connects the inner space of the retainer to the second annular passage; as well as A transverse passage is formed in the retainer and connects the second annular passage to the inner space of the housing.

3. The electric valve according to claim 1 or 2, characterized in that, The size of the gap is smaller than the clearance of the drive mechanism.

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