Motorised valve

Abstract

Provided is an electric valve capable of suppressing eccentric wear of a rotating member. An electric valve (1) includes a planetary gear device (75) coupled to a rotor (51); a drive shaft (80) coupled to the planetary gear device (75); and a drive shaft support portion (61) fixed to a valve main body. The planetary gear device (75) includes first to third sun gears (71a, 72a, 73a), first to third planetary gears (71b, 72b, 73b), first to third planetary gear carriers (71c, 72c, 73c), and a fixed gear (62). The drive shaft (80) includes an external thread (83c), and the drive shaft support portion (61) includes an internal thread (61c). The drive shaft support portion (61) and the fixed gear (62) are formed integrally.

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 having a valve port, a valve core disposed toward the valve port, and a housing engaged with the valve body. A stator is disposed on the outer side of the housing. A rotor is disposed on the inner side of the housing. Furthermore, the electric valve includes: a planetary gear assembly for reducing the rotational speed of the rotor, a drive shaft connected to the planetary gear assembly, and a drive shaft support member.

[0003] The planetary gear unit includes: a sun gear connected to a rotor, planetary gears meshing with the sun gear, a planetary gear carrier supporting the planetary gears so that they can rotate, a fixed gear serving as a fixed internal gear meshing with the planetary gears, and an output gear serving as an internal gear meshing with the planetary gears.

[0004] The drive shaft is connected to the output gear. An external thread is formed on the drive shaft. An internal thread is formed on the drive shaft support component. The external thread of the drive shaft engages with the internal thread of the drive shaft support component. When the drive shaft rotates via the planetary gear mechanism, it moves towards or away from the valve port through threaded feed. The valve core moves along with the movement of the drive shaft.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2012-197849

[0008] The technical problem that the invention aims to solve

[0009] In the aforementioned electric valve, the fixed gear is fixed to the valve body via a cylindrical gear housing. The drive shaft support component is also fixed to the valve body. The central axis of the fixed gear and the central axis of the internal thread of the drive shaft support component are coaxial. However, the central axis of the fixed gear and the central axis of the internal thread of the drive shaft support component may misalign due to component precision or assembly precision. This can cause uneven wear on rotating parts such as gears and drive shafts, shortening the product's lifespan. Summary of the Invention

[0010] Therefore, the object of the present invention is to provide an electric valve capable of suppressing uneven wear of rotating parts.

[0011] To achieve the above objectives, the electric valve of the present invention comprises: a valve body having a valve port; a valve core disposed opposite to the valve port; a rotor configured to rotate relative to the valve body; a planetary gear assembly connected to the rotor; a drive shaft connected to the planetary gear assembly; and a drive shaft support fixed to the valve body, wherein the planetary gear assembly comprises: a sun gear, planetary gears meshing with the sun gear, a planetary gear carrier supporting the planetary gears to be rotatable, and a fixed internal gear meshing with the planetary gears; one of the drive shaft and the drive shaft support has an external thread, and the other has an internal thread for the external thread to be screwed into; when the drive shaft rotates via the planetary gear assembly, the drive shaft moves toward or away from the valve port; and the drive shaft support and the fixed internal gear are integrally formed.

[0012] In this invention, preferably, the drive shaft support and the fixed internal gear are made of synthetic resin and are integrally formed.

[0013] In this invention, preferably, it also includes a metal component that engages with the valve body, the drive shaft support and the fixed internal gear are made of synthetic resin, and the drive shaft support, the fixed internal gear and the metal component are integrally formed.

[0014] In this invention, preferably, it also includes a metal component that is pressed into the valve body, the drive shaft support and the fixed internal gear are made of synthetic resin, and the drive shaft support, the fixed internal gear and the metal component are integrally formed.

[0015] In this invention, preferably, the planetary gear device has N gear sets, each consisting of a sun gear, a planetary gear, and a planetary gear carrier, where N is a natural number greater than or equal to 2. The rotor is coaxially connected to the sun gear of the first gear set, and the planetary gear carrier of the Kth gear set is coaxially connected to the sun gear of the (K+1)th gear set, where K = 1, ..., N-1. The planetary gear carrier of the Nth gear set is coaxially connected to the drive shaft. The planetary gear device has only one fixed internal gear, and the planetary gears of each of the N gear sets mesh with the fixed internal gear.

[0016] The effects of the invention

[0017] According to the present invention, the drive shaft support and the fixed internal gear of the planetary gear assembly are integrally formed. Therefore, since the drive shaft support and the fixed internal gear of the planetary gear assembly are integrally formed as a single part, the central axis of the thread (external or internal thread) of the drive shaft support and the central axis of the fixed internal gear can be coaxially aligned with high precision. This suppresses uneven wear of rotating parts. Furthermore, it suppresses the reduction in rotational transmission efficiency caused by eccentricity of rotating parts. Additionally, the number of parts in the electric valve is reduced, improving the assemblability of the electric valve. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view showing the open state of the electric valve according to the first embodiment of the present invention.

[0019] Figure 2 It means Figure 1 A cross-sectional view of the electric valve in the closed state.

[0020] Figure 3 It's enlarged. Figure 1 A cross-sectional view of a portion of an electric valve.

[0021] Figure 4 It includes Figure 1 A perspective view of a portion of the cross-section of the support component of the electric valve.

[0022] Figure 5 yes Figure 1 An exploded perspective view of the valve core drive unit of an electric valve.

[0023] Figure 6 It means as Figure 1 A cross-sectional view of a modified electric valve in the open state.

[0024] Figure 7 It means Figure 6 A cross-sectional view of the electric valve in the closed state.

[0025] Figure 8 It's enlarged. Figure 6 A cross-sectional view of a portion of an electric valve.

[0026] Figure 9 This is a cross-sectional view showing the open state of the electric valve according to the second embodiment of the present invention.

[0027] Figure 10 It means Figure 9 A cross-sectional view of the electric valve in the closed state.

[0028] Figure 11 It's enlarged. Figure 9 A cross-sectional view of a portion of an electric valve.

[0029] Figure 12 It includes Figure 9 A perspective view of a portion of the cross-section of the support component of the electric valve.

[0030] Figure 13 yes Figure 9 An exploded perspective view of the valve core drive unit of an electric valve.

[0031] Figure 14 It means as Figure 9 A cross-sectional view of a modified electric valve in the open state.

[0032] Figure 15 It means Figure 14 A cross-sectional view of the electric valve in the closed state.

[0033] Figure 16 It's enlarged. Figure 14 A cross-sectional view of a portion of an electric valve.

[0034] Symbol Explanation

[0035] 1, 1A, 2, 2A… Electric valve, 10… Valve body, 10a… Upper part, 11… Peripheral wall part, 12… Bottom wall part, 13… Valve chamber, 14… Valve port, 15… Plane, 16… First conduit, 17… Second conduit, 20… Bushing, 21… First cylindrical part, 22… Stepped part, 23… Second cylindrical part, 24… Flange part, 30… Housing, 32… Protrusion, 35… Connecting part, 40… Valve core, 41… Rod, 42… Valve part, 43… Spring receiving part, 43a… Flange part, 44… Ball receiving part, 44a… Flat plate part, 44b… Protrusion, 50… Valve core drive part, 51… Rotor, 52… Connecting part, 53… 54… rotor shaft, 55… bearing component, 60… support component, 61… drive shaft support, 61a… inner circumferential surface, 61c… internal thread, 62… fixed gear, 63… metal component, 63a… through hole, 70… gear mechanism, 71… first gear set, 71a… first sun gear, 71b… first planetary gear, 71c… first planetary gear carrier, 71c1… first gear carrier body, 71c2… first support column, 71c3… first auxiliary column, 71c4… first connecting plate, 72… second gear set, 72a… second sun gear, 72b… second planetary gear, 72c… second planetary gear carrier. 72c1…Second gear carrier body, 72c2…Second support column, 72c3…Second auxiliary column, 72c4…Second connecting plate, 73…Third gear set, 73a…Third sun gear, 73b…Third planetary gear, 73c…Third planetary gear carrier, 73c1…Third gear carrier body, 73c2…Third support column, 73c3…Third auxiliary column, 73c4…Third connecting plate, 75…Planetary gear assembly, 80…Drive shaft, 80a…Shaft hole, 81…First part, 82…Second part, 83…Third part, 83c…External thread, 85…Ball, 86…Valve opening spring, 90…Stator unit, 91…Stator, 92…cover, 93…mounting part, 93a…fitting hole, 180…output shaft, 180a…shaft hole, 181…first part, 182…second part, 183…slit, 185…drive shaft, 186…cylindrical part, 186c…external thread, 187…flat part, 260…support member, 261…drive shaft support, 261a…inner circumferential surface, 261c…internal thread, 262…fixed gear, 263…metal part, 264…small diameter cylindrical part, 264a…through hole, 265…large diameter cylindrical part, 275…planetary gear assembly, A1…first assembly, A2…second assembly, A3…third assembly Detailed Implementation

[0036] (First Embodiment)

[0037] The following is for reference Figures 1 to 8The electric valve of the first embodiment of the present invention will be described below. The electric valve 1 of this embodiment is used, for example, to adjust the refrigerant flow rate in a refrigeration cycle or the like.

[0038] Figure 1 , Figure 2 This is a cross-sectional view of the electric valve according to the first embodiment of the present invention. Figure 1 An electric valve indicating its open state. Figure 2 An electric valve indicating the closed state. Figure 3 It's enlarged. Figure 1 A cross-sectional view of a portion of an electric valve (mainly the valve core drive section). Figure 4 It includes Figure 1 A perspective view of a portion of the cross-section of the support component of the electric valve. Figure 5 yes Figure 1 An exploded perspective view of the valve core drive unit of an electric valve. Figure 6 , Figure 7 Is as Figure 1 A cross-sectional view of a modified electric valve. Figure 6 An electric valve indicating its open state. Figure 7 An electric valve indicating the closed state. Figure 8 It's enlarged. Figure 6 A cross-sectional view of a portion (mainly the valve core drive section) of an electric valve. Figure 3 , Figure 8 The stator unit description is omitted in the text.

[0039] like Figure 1 , Figure 2 As shown, the electric valve 1 of this embodiment includes: valve body 10, bushing 20, housing 30, valve core 40, valve core drive part 50, and stator unit 90.

[0040] The valve body 10 has a bottomed cylindrical shape. The valve body 10 has a peripheral wall portion 11 and a bottom wall portion 12. The valve body 10 has a valve chamber 13 on its inner side. The bottom wall portion 12 has a circular valve port 14. The valve port 14 is connected to the valve chamber 13. An upward-facing annular plane 15 is formed on the inner peripheral surface of the peripheral wall portion 11. A first conduit 16 engages with the peripheral wall portion 11. The first conduit 16 penetrates the peripheral wall portion 11 in a direction orthogonal to the axis L. The first conduit 16 is connected to the valve chamber 13. A second conduit 17 engages with the bottom wall portion 12. The second conduit 17 is connected to the valve port 14. The valve body 10 is made of metals such as stainless steel or brass.

[0041] The bushing 20 has a stepped cylindrical shape. The bushing 20 has a first cylindrical portion 21, a stepped portion 22, a second cylindrical portion 23, and a flange portion 24 arranged sequentially from bottom to top. The stepped portion 22 and the flange portion 24 have annular flat plate shapes. The outer diameter of the first cylindrical portion 21 is smaller than the inner diameter of the second cylindrical portion 23. The upper end of the first cylindrical portion 21 is continuously disposed on the inner periphery of the stepped portion 22. The lower end of the second cylindrical portion 23 is continuously disposed on the outer periphery of the stepped portion 22. The upper end of the second cylindrical portion 23 is continuously disposed on the inner periphery of the flange portion 24. The bushing 20 is disposed inside the valve body 10. The first cylindrical portion 21 and the valve port 14 are spaced apart in the vertical direction (axis L direction). The flange portion 24 is in contact with the plane 15 of the valve body 10.

[0042] 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 plate engagement member 35. The upper part 10a of the valve body 10 (i.e., the upper part of the peripheral wall 11) is disposed inside the engagement member 35. The valve body 10 engages with the inner periphery of the engagement member 35.

[0043] The valve core 40 includes a rod 41, a valve portion 42, a spring receiving portion 43, and a ball receiving portion 44. The rod 41 is cylindrical. The outer diameter of the rod 41 is slightly smaller than the inner diameter of the first cylindrical portion 21 of the bushing 20. The rod 41 is disposed inside the first cylindrical portion 21. The rod 41 is supported by the first cylindrical portion 21 and is movable in the vertical direction. The valve portion 42 has a frustum-shaped outer diameter that gradually decreases from top to bottom. The valve portion 42 is continuously disposed at the lower end of the rod 41. The maximum outer diameter of the valve portion 42 is greater than the outer diameter of the rod 41. The valve portion 42 is configured to face the valve port 14 in the vertical direction. The spring receiving portion 43 is cylindrical. The outer diameter of the spring receiving portion 43 is the same as the outer diameter of the rod 41. The spring receiving portion 43 engages with the upper end of the rod 41. The spring receiving portion 43 has an annular flange portion 43a that protrudes radially outward from its outer circumference. The ball receiving portion 44 has a circular flat plate portion 44a and a protrusion 44b continuously provided on the lower surface of the flat plate portion 44a. The protrusion 44b fits into a hole formed in the spring receiving portion 43. The valve core 40 changes the opening area of ​​the valve port 14 steplessly by moving the valve portion 42 relative to the valve port 14. The valve core 40 can also close the valve port 14 (i.e., the opening area can also be set to 0).

[0044] The valve core drive unit 50 moves the valve core 40 in the vertical direction. The valve core drive unit 50 includes: a rotor 51, a connecting part 52, a rotor shaft 53, a bearing part 54, a rotor spring 55, a support part 60, a gear mechanism 70, a drive shaft 80, a ball 85, and a valve opening spring 86.

[0045] The rotor 51 has a cylindrical shape. On the outer circumferential surface of the rotor 51, the N pole and S pole are alternately arranged in the circumferential direction. The outer diameter of the rotor 51 is smaller than the inner diameter of the housing 30. The rotor 51 is rotatably disposed inside the housing 30. A circular plate-shaped connecting member 52 is coaxially joined to the upper end of the rotor 51. The connecting member 52 is made of synthetic resin. The connecting member 52 closes the upper end of the rotor 51. The rotor shaft 53 passes through the center of the connecting member 52. A bearing member 54 is disposed above the rotor 51, supporting the upper end of the rotor shaft 53 for rotation. A rotor spring 55 is disposed between the connecting member 52 and the bearing member 54. The rotor spring 55 is a compression helical spring. The rotor spring 55 presses the connecting member 52 (rotor 51) downwards.

[0046] The support component 60 is a part integrally formed from a synthetic resin part and a metal part by injection molding (insert molding). The support component 60 includes: a drive shaft support 61, a fixed gear 62, and a metal component 63. The drive shaft support 61 and the fixed gear 62 are made of synthetic resins such as polyphenylene sulfide (PPS) and polyether ether ketone (PEEK). The metal component 63 is made of metals such as brass and stainless steel. The valve body 10 and the metal component 63 are preferably made of the same metal. In this embodiment, both the valve body 10 and the metal component 63 are made of brass. The valve body 10 is made of an alloy, and the metal component 63 is preferably made of another alloy with the same main component but different component ratios.

[0047] The drive shaft support 61 has a cylindrical shape. The outer diameter of the drive shaft support 61 is the same as the inner diameter of the upper part 10a of the valve body 10. The drive shaft support 61 is coaxially disposed on the inner side of the upper part 10a of the valve body 10. An annular gap is formed between the lower part of the outer peripheral surface of the drive shaft support 61 and the inner peripheral surface of the upper part 10a of the valve body 10, and this gap connects with the transverse hole formed in the upper part 10a. The flange 24 of the bushing 20 is held between the drive shaft support 61 and the plane 15 of the valve body 10. An internal thread 61c is formed on the lower part of the inner peripheral surface 61a of the drive shaft support 61.

[0048] The fixed gear 62 has a cylindrical shape. The outer diameter of the fixed gear 62 is the same as the outer diameter of the upper part 10a of the valve body 10. The lower end of the fixed gear 62 is continuously disposed on the upper end of the drive shaft support part 61. The fixed gear 62 is a fixed internal gear with teeth formed on its inner circumferential surface.

[0049] The metal component 63 has an annular flat plate shape. The outer diameter of the metal component 63 is the same as the outer diameter of the upper part 10a of the valve body 10. The metal component 63 is disposed in a continuous arrangement between the drive shaft support 61 and the fixed gear 62. The drive shaft support 61, the fixed gear 62, and the metal component 63 are arranged coaxially. The metal component 63 is welded to the upper part 10a of the valve body 10. Alternatively, in the support component 60, the metal component 63 may be omitted, and the drive shaft support 61 may be joined to the upper part 10a of the valve body 10 by adhesive or the like.

[0050] The metal component 63 has a plurality of through holes 63a arranged at intervals in the circumferential direction. During injection molding of the support component 60, the plurality of through holes 63a are filled with synthetic resin. As a result, in the electric valve 1, the rotation of the drive shaft support 61 and the fixed gear 62 relative to the metal component 63 is restricted.

[0051] The gear mechanism 70 and the fixed gear 62 together constitute the planetary gear device 75. The gear mechanism 70 has: a first gear set 71, a second gear set 72, and a third gear set 73.

[0052] The first gear set 71 includes a first sun gear 71a, a plurality of first planetary gears 71b, and a first planetary gear carrier 71c. The first sun gear 71a is coaxially connected to the lower surface of the connecting member 52. The first sun gear 71a is made of synthetic resin and is integrally formed with the connecting member 52. The plurality of first planetary gears 71b mesh with the first sun gear 71a and the fixed gear 62. The first planetary gear carrier 71c includes a first gear carrier body 71c1, a plurality of first support columns 71c2, a plurality of first auxiliary columns 71c3, and a first connecting plate 71c4. The first gear carrier body 71c1 has a circular plate shape. The plurality of first support columns 71c2 and the plurality of first auxiliary columns 71c3 are erected alternately in a circumferential arrangement on the upper surface of the first gear carrier body 71c1. The plurality of first support columns 71c2 support the plurality of first planetary gears 71b so that they can rotate. The first connecting plate 71c4 has an annular plate shape. The first connecting plate 71c4 connects the upper ends of the plurality of first support columns 71c2 to the upper ends of the plurality of first auxiliary columns 71c3. The rotor shaft 53 passes through the center of the first sun gear 71a and the center of the first gear carrier body 71c1.

[0053] The second gear set 72 includes a second sun gear 72a, a plurality of second planetary gears 72b, and a second planetary gear carrier 72c. The second sun gear 72a is coaxially connected to the lower surface of the first gear carrier body 71c1. The second sun gear 72a is made of synthetic resin and is integrally formed with the first gear carrier body 71c1. The plurality of second planetary gears 72b mesh with the second sun gear 72a and the fixed gear 62. The second planetary gear carrier 72c includes a second gear carrier body 72c1, a plurality of second support columns 72c2, a plurality of second auxiliary columns 72c3, and a second connecting plate 72c4. The second gear carrier body 72c1 has a circular plate shape. The plurality of second support columns 72c2 and the plurality of second auxiliary columns 72c3 are alternately arranged circumferentially on the upper surface of the second gear carrier body 72c1. The plurality of second support columns 72c2 support the plurality of second planetary gears 72b so that they can rotate. The second connecting plate 72c4 has an annular plate shape. The second connecting plate 72c4 connects the upper ends of the plurality of second support columns 72c2 to the upper ends of the plurality of second auxiliary columns 72c3. The rotor shaft 53 passes through the center of the second sun gear 72a and the center of the second gear carrier body 72c1.

[0054] The third gear set 73 includes: a third sun gear 73a, multiple third planetary gears 73b, and a third planetary gear carrier 73c. ​​The third sun gear 73a is coaxially connected to the lower surface of the second gear carrier body 72c1. The third sun gear 73a is made of synthetic resin and is integrally formed with the second gear carrier body 72c1. The multiple third planetary gears 73b mesh with the third sun gear 73a and the fixed gear 62. The third planetary gear carrier 73c includes: a third gear carrier body 73c1, multiple third support columns 73c2, multiple third auxiliary columns 73c3, and a third connecting plate 73c4. The third gear carrier body 73c1 has a circular plate shape. The multiple third support columns 73c2 and multiple third auxiliary columns 73c3 are erected alternately in a circumferential arrangement on the upper surface of the third gear carrier body 73c1. The multiple third support columns 73c2 support the multiple third planetary gears 73b so that they can rotate. The third connecting plate 73c4 has an annular plate shape. The third connecting plate 73c4 connects the upper ends of the multiple third support columns 73c2 and the upper ends of the multiple third auxiliary columns 73c3. The rotor shaft 53 passes through the center of the third sun gear 73a.

[0055] The drive shaft 80 is formed, for example, by machining a cylindrical metal rod. The drive shaft 80 has a first portion 81, a second portion 82, and a third portion 83. The first portion 81, second portion 82, and third portion 83 are arranged sequentially from top to bottom. The first portion 81 is connected to the third gear carrier body 73c1. Specifically, the first portion 81 has a knurled outer circumferential surface and is pressed into a hole formed in the center of the third gear carrier body 73c1. The second portion 82 has a cylindrical shape. The outer diameter of the second portion 82 is slightly smaller than the inner diameter of the drive shaft support portion 61. The second portion 82 is disposed inside the drive shaft support portion 61. The second portion 82 is supported by the drive shaft support portion 61 and is rotatable and movable in the vertical direction. The third portion 83 has a cylindrical shape. The outer diameter of the third portion 83 is smaller than the outer diameter of the second portion 82. An external thread 83c is formed on the outer circumferential surface of the third portion 83. The external thread 83c engages with the internal thread 61c of the drive shaft support portion 61. Alternatively, the drive shaft support 61 may have external threads, and the drive shaft 80 may have internal threads. The lower end of the rotor shaft 53 is disposed in the shaft hole 80a extending from the first portion 81 to the second portion 82.

[0056] Ball 85 is joined to the lower end face of the third part 83. Ball 85 is connected to the flat plate part 44a of the ball receiving part 44.

[0057] The valve opening spring 86 is positioned between the flange portion 43a of the spring receiving portion 43 and the stepped portion 22 of the bushing 20. The valve opening spring 86 is a compression helical spring. The valve opening spring 86 presses the valve core 40 (flange portion 43a) upward.

[0058] The stator unit 90 includes a stator 91, a cover 92, and multiple mounting portions 93. The stator 91 has a cylindrical shape. The cover 92 has a cap shape. The stator 91 is disposed inside the cover 92. The housing 30 is disposed inside the stator 91. The stator 91 and the rotor 51 together constitute a stepper motor. The multiple mounting portions 93 are elastically deformable metal sheets. The multiple mounting portions 93 engage with the cover 92. The multiple mounting portions 93 correspond to multiple protrusions 32 formed on the housing 30. The multiple mounting portions 93 have fitting holes 93a for engaging the corresponding protrusions 32. By engaging the multiple protrusions 32 into the fitting holes 93a of the multiple mounting portions 93, the stator unit 90 is mounted on the housing 30.

[0059] In the electric valve 1, the valve body 10 (peripheral wall 11, bottom wall 12, valve port 14), bushing 20, housing 30, valve core 40, rotor 51, connecting component 52, rotor shaft 53, support component 60 (drive shaft support 61 (internal thread 61c), fixed gear 62, metal component 63), first sun gear 71a, first planetary gear carrier 71c, second sun gear 72a, second planetary gear carrier 72c, third sun gear 73a, third planetary gear carrier 73c, and drive shaft 80 are all aligned on axis L.

[0060] Next, the operation of electric valve 1 will be explained.

[0061] In the electric valve 1, current flows through the stator 91, causing the rotor 51 to rotate in one direction. The rotation of the rotor 51 is reduced in speed by the planetary gear mechanism 75 and transmitted to the drive shaft 80. Through the threaded feed action between the external thread 83c of the drive shaft 80 and the internal thread 61c of the drive shaft support 61, the drive shaft 80, gear mechanism 70, connecting component 52, and rotor 51 move downwards. The valve core 40 is pressed downwards by the drive shaft 80, thereby reducing the opening area of ​​the valve port 14. When the valve core 40 closes the valve port 14, the electric valve 1 is in the closed state.

[0062] In electric valve 1, current flows through stator 91, causing rotor 51 to rotate in the opposite direction. The rotation of rotor 51 is reduced by planetary gear mechanism 75 and transmitted to drive shaft 80. Through the threaded feed action between the external thread 83c of drive shaft 80 and the internal thread 61c of drive shaft support 61, drive shaft 80, gear mechanism 70, connecting part 52, and rotor 51 move upward. Valve core 40 is pressed upward by valve opening spring 86, thereby increasing the opening area of ​​valve port 14. When valve core 40 opens valve port 14, electric valve 1 is in the open state.

[0063] Next, the manufacturing method of electric valve 1 will be described.

[0064] The metal part 63 is placed in the cavity of the mold for forming the support part 60, and synthetic resin is injected into and filled into the cavity to obtain the support part 60.

[0065] The first conduit 16 and the second conduit 17 are brazed to the valve body 10. The upper part 10a of the valve body 10 is inserted into the inner side of the connecting member 35, and the upper part 10a is welded to the inner periphery of the connecting member 35. The rod 41 of the valve core 40 is inserted into the first cylindrical part 21 of the bushing 20 and the valve opening spring 86. The spring receiving part 43 is joined to the rod 41, and the ball receiving part 44 is fitted into the spring receiving part 43. The bushing 20 with the valve core 40 assembled is positioned inside the valve body 10. The drive shaft support part 61 of the support member 60 is inserted into the upper part 10a of the valve body 10, and the flange part 24 of the bushing 20 is held by the plane 15 of the valve body 10 and the drive shaft support part 61. The metal part 63 of the support member 60 is welded to the upper part 10a of the valve body 10.

[0066] A first assembly A1 is obtained by assembling multiple first planetary gears 71b, a first planetary gear carrier 71c, and a second sun gear 72a together. A second assembly A2 is obtained by assembling multiple second planetary gears 72b, a second planetary gear carrier 72c, and a third sun gear 73a together. A third assembly A3 is obtained by assembling multiple third planetary gears 73b, a third planetary gear carrier 73c, a drive shaft 80, and a ball joint 85 together. The third assembly A3, the second assembly A2, and the first assembly A1 are sequentially assembled onto the support member 60.

[0067] The rotor shaft 53 is inserted into the shaft hole 80a of the drive shaft 80 by passing through the connecting member 52, the first sun gear 71a, the first planetary gear carrier 71c, the second sun gear 72a, the second planetary gear carrier 72c, and the third sun gear 73a. The rotor spring 55 is positioned between the connecting member 52, which is connected to the rotor 51, and the bearing member 54, and the upper end of the rotor shaft 53 is inserted into the bearing member 54.

[0068] The upper part 10a of the valve body 10, the rotor 51, the connecting part 52, the rotor shaft 53, the bearing part 54, the rotor spring 55, the support part 60, and the gear mechanism 70 are inserted into the inside of the housing 30. The lower end of the housing 30 is welded to the outer periphery of the connecting part 35. The stator unit 90 is installed on the housing 30. Thus, the electric valve 1 is completed.

[0069] The electric valve 1 of this embodiment includes: a valve body 10 having a valve port 14, a valve core 40 disposed opposite to the valve port, a rotor 51 configured to rotate relative to the valve body 10, a planetary gear assembly 75 connected to the rotor 51, a drive shaft 80 connected to the planetary gear assembly 75, and a drive shaft support 61 fixed to the valve body 10. The planetary gear assembly 75 includes: a first gear set 71 (a first sun gear 71a, a plurality of first planetary gears 71b, and a first planetary gear carrier 71c), a second gear set 72 (a second sun gear 72a, a plurality of second planetary gears 72b, and a second planetary gear carrier 72c), a third gear set 73 (a third sun gear 73a, a third planetary gear 73b, and a third planetary gear carrier 73c), and a fixed gear 62 meshing with the first planetary gears 71b, the second planetary gears 72b, and the third planetary gear 73b. The drive shaft 80 has an external thread 83c. The drive shaft support 61 has an internal thread 61c for threading the external thread 83c. When the drive shaft 80 rotates via the planetary gear assembly 75, the drive shaft 80 moves downward (towards the valve port 14) or upward (away from the valve port 14). Furthermore, the drive shaft support 61 and the fixed gear 62 are made of synthetic resin and are integrally molded.

[0070] Therefore, the drive shaft support 61 and the fixed gear 62 of the planetary gear assembly 75 are integrally formed as a single part, enabling high-precision coaxial alignment of the central axis of the internal thread 61c of the drive shaft support 61 and the central axis of the fixed gear 62. This suppresses uneven wear of rotating parts such as gears. Furthermore, it suppresses the reduction in rotational transmission efficiency caused by the eccentricity of rotating parts. Additionally, the reduced number of parts in the electric valve 1 improves its assemblability.

[0071] Furthermore, the electric valve 1 has a metal part 63 that engages with the valve body 10. The drive shaft support 61, the fixed gear 62, and the metal part 63 are integrally formed. This allows the drive shaft support 61 and the fixed gear 62 to be reliably fixed to the valve body 10.

[0072] Furthermore, the rotor 51 is coaxially connected to the first sun gear 71a. The first planetary gear carrier 71c is coaxially connected to the second sun gear 72a. The second planetary gear carrier 72c is coaxially connected to the third sun gear 73a. The third planetary gear carrier 73c is coaxially connected to the drive shaft 80. Multiple first planetary gears 71b, multiple second planetary gears 72b, and multiple third planetary gears 73b mesh with the fixed gear 62. Thus, the planetary gear assembly 75 has a structure that combines three stages of a 2K-H type planetary gear mechanism, achieving a larger reduction ratio. Furthermore, by having the first gear set 71, the second gear set 72, and the third gear set 73 share the fixed gear 62, the planetary gear assembly 75 can be configured with a simpler structure.

[0073] Furthermore, the planetary gear assembly 75 can have a single-stage or two-stage 2K-H type planetary gear mechanism, or it can have four or more stages. In the structure of the planetary gear assembly 75 having N gear sets (where N is a natural number of 2 or more) consisting of a sun gear, planet gears, and a planetary gear carrier, the rotor 51 is coaxially connected to the sun gear of the first gear set via a connecting member 52, the planetary gear carrier of the Kth gear set (where K = 1, ..., N-1) is coaxially connected to the sun gear of the K+1th gear set, and the planetary gear carrier of the Nth gear set is coaxially connected to the drive shaft 80. Moreover, the planetary gear assembly 75 has only one fixed gear 62, and the planet gears of each of the N gear sets mesh with the fixed gear 62. Alternatively, the planetary gear assembly 75 can replace the 2K-H type planetary gear mechanism with, for example, the 3K type differential planetary gear mechanism disclosed in Patent Document 1.

[0074] Figures 6-8 Electric valve 1A is shown as a variation of the electric valve 1 described above. Electric valve 1A has the same structure as electric valve 1 except that (1) it has an output shaft 180 and a drive shaft 185 instead of a drive shaft 80, and (2) the rotor spring 55 is omitted. In the description of electric valve 1A, the same symbols are used for structures that are the same as those in electric valve 1, and detailed descriptions are omitted.

[0075] The output shaft 180 is formed, for example, by machining a cylindrical metal rod. The output shaft 180 has a first portion 181 and a second portion 182. The first portion 181 and the second portion 182 are arranged sequentially from top to bottom. The first portion 181 is connected to the third gear carrier body 73c1. Specifically, the first portion 181 has a knurled outer circumferential surface and is pressed into a hole formed in the center of the third gear carrier body 73c1. The second portion 182 has a cylindrical shape. A slit 183 extending in the vertical direction is formed in the lower part of the second portion 182. The outer diameter of the second portion 182 is slightly smaller than the inner diameter of the drive shaft support portion 61. The second portion 182 is disposed inside the drive shaft support portion 61. The second portion 182 is supported by the drive shaft support portion 61 to be rotatable. The lower end of the rotor shaft 53 is disposed in the shaft hole 180a extending from the first portion 181 to the second portion 182.

[0076] The drive shaft 185 is formed, for example, by machining a cylindrical metal rod. The drive shaft 185 has a cylindrical portion 186 and a flat portion 187. The cylindrical portion 186 and the flat portion 187 are arranged sequentially from bottom to top. An external thread 186c is formed on the outer circumferential surface of the cylindrical portion 186. The external thread 186c engages with the internal thread 61c of the drive shaft support portion 61. The thickness of the flat portion 187 is slightly less than the width of the slit 183 of the output shaft 180. The flat portion 187 is configured to be movable in the vertical direction inside the slit 183 of the output shaft 180. The rotation of the output shaft 180 is transmitted to the drive shaft 185 through the slit 183 and the flat portion 187, enabling the drive shaft 185 to move in the vertical direction relative to the output shaft 180. When the drive shaft 185 rotates, the drive shaft 185 moves in the vertical direction due to the threaded feed action between the external thread 186c and the internal thread 61c of the drive shaft support 61. Furthermore, in the electric valve 1A, the output shaft 180, gear mechanism 70, connecting member 52, and rotor 51 do not move in the vertical direction.

[0077] In electric valve 1A, it can also achieve the same effect as electric valve 1 mentioned above.

[0078] (Second Embodiment)

[0079] The following is for reference Figures 9-16 The electric valve of the second embodiment of the present invention will now be described. The electric valve 2 of this embodiment is also used in the same manner as the electric valve 1, such as in a refrigeration cycle.

[0080] Figure 9 , Figure 10 This is a cross-sectional view of the electric valve according to the second embodiment of the present invention. Figure 9 An electric valve indicating its open state. Figure 10 An electric valve indicating the closed state. Figure 11 It's enlarged. Figure 9 A cross-sectional view of a portion of an electric valve (mainly the valve core drive section). Figure 12 It includes Figure 9 A perspective view of a portion of the cross-section of the support component of the electric valve. Figure 13 yes Figure 9 An exploded perspective view of the valve core drive unit of an electric valve. Figure 14 , Figure 15 Is as Figure 9 A cross-sectional view of a modified electric valve. Figure 14 An electric valve indicating its open state. Figure 15 An electric valve indicating the closed state. Figure 16 It's enlarged. Figure 14 A cross-sectional view of a portion (mainly the valve core drive section) of an electric valve. Figure 11 , Figure 16 The stator unit description is omitted in the text.

[0081] The electric valve 2 of the second embodiment has the same structure as the electric valve 1, except that it has a support member 260 that has a different structure than the support member 60, which replaces the support member 60. In the description of the electric valve 2, the same symbols are used for structures that are the same as those in the electric valve 1, and detailed descriptions are omitted.

[0082] The support component 260 is a single part integrally formed by injection molding (insert molding) a synthetic resin part and a metal part. The support component 260 includes: a drive shaft support 261, a fixed gear 262, and a metal component 263. The drive shaft support 261 and the fixed gear 262 are made of synthetic resins such as PPS and PEEK. The metal component 263 is made of metals such as brass or stainless steel. The valve body 10 and the metal component 263 are preferably made of the same metal. Alternatively, the valve body 10 may be made of an alloy, and the metal component 263 may be made of another alloy with the same main component but different composition or component ratio.

[0083] The drive shaft support portion 261 has a cylindrical shape. An internal thread 261c is formed on the lower part of the inner circumferential surface 261a of the drive shaft support portion 261. The external thread 83c of the drive shaft 80 engages with the internal thread 261c.

[0084] The fixed gear 262 has a cylindrical shape. The outer diameter of the fixed gear 262 is larger than the outer diameter of the drive shaft support portion 261. The lower end of the fixed gear 262 is continuously disposed at the upper end of the drive shaft support portion 261. The fixed gear 262 is a fixed internal gear with teeth formed on its inner circumferential surface. The fixed gear 262 is substantially the same as the fixed gear 62 described above. In the electric valve 2, the gear mechanism 70 and the fixed gear 262 together constitute the planetary gear device 275.

[0085] Metal component 263 has a stepped cylindrical shape. Metal component 263 has a small-diameter cylindrical portion 264 and a large-diameter cylindrical portion 265. The small-diameter cylindrical portion 264 and the large-diameter cylindrical portion 265 are arranged sequentially from bottom to top. The outer diameter of the small-diameter cylindrical portion 264 is slightly larger than the inner diameter of the upper portion 10a of the valve body 10. A drive shaft support portion 261 is disposed inside the small-diameter cylindrical portion 264. The small-diameter cylindrical portion 264 has: a longitudinal hole extending upward from its lower end face; and an annular groove formed circumferentially on its outer peripheral surface and connected to the upper end of the longitudinal hole. The annular groove connects to a transverse hole formed in the upper portion 10a of the valve body 10. The outer diameter of the large-diameter cylindrical portion 265 is larger than the outer diameter of the upper portion 10a of the valve body 10. The lower part of a fixed gear 262 is disposed inside the large-diameter cylindrical portion 265. The small-diameter cylindrical portion 264 is coaxially disposed inside the upper portion 10a of the valve body 10. The small-diameter cylindrical portion 264 is pressed into the upper portion 10a of the valve body 10. The flange portion 24 of the bushing 20 is held between the small-diameter cylindrical portion 264 and the plane 15 of the valve body 10. The drive shaft support portion 261, the fixed gear 262, and the metal component 263 are coaxially disposed.

[0086] The small-diameter cylindrical portion 264 has a plurality of through holes 264a arranged at intervals in the circumferential direction. During injection molding of the support member 260, the plurality of through holes 264a are filled with synthetic resin. As a result, in the electric valve 2, the drive shaft support portion 261 and the fixed gear 262 are prevented from detaching from the metal part 263.

[0087] In electric valve 2, it also plays the same role as electric valve 1 mentioned above.

[0088] Furthermore, the electric valve 2 has a metal component 263 that is pressed into the valve body 10. The drive shaft support 261, the fixed gear 262, and the metal component 263 are integrally formed. This allows the drive shaft support 261 and the fixed gear 262 to be reliably fixed to the valve body 10.

[0089] Figures 14-16 Electric valve 2A is shown as a variation of the electric valve 2 described above. Electric valve 2A has the same structure as electric valve 1A, except that it has a support member 260 instead of support member 60. Electric valve 2A is composed of components already described, therefore detailed descriptions are omitted.

[0090] In electric valve 2A, it also plays the same role as electric valve 2 mentioned above.

[0091] The embodiments of the present invention have been described above, but the present invention is not limited to the structure of the embodiments. Embodiments created by adding or deleting constituent elements, making design changes, or appropriately combining features of the embodiments, 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 port; a valve core disposed opposite to the valve port; a rotor configured to rotate relative to the valve body; a planetary gear assembly connected to the rotor; a drive shaft connected to the planetary gear assembly; and a drive shaft support fixed to the valve body, characterized in that... The planetary gear assembly includes: a sun gear, planetary gears meshing with the sun gear, a planetary gear carrier supporting the planetary gears so that they can rotate, and a fixed internal gear meshing with the planetary gears. One of the drive shaft and the drive shaft support has an external thread, and the other has an internal thread for engaging the external thread. When the drive shaft rotates via the planetary gear assembly, the drive shaft moves toward or away from the valve port. The drive shaft support and the fixed internal gear are integrally formed. It also has a metal component that engages with the valve body. The drive shaft support and the fixed internal gear are made of synthetic resin. The drive shaft support, the fixed internal gear, and the metal component are integrally formed.

2. An electric valve comprising: a valve body having a valve port; a valve core disposed opposite to the valve port; a rotor configured to rotate relative to the valve body; a planetary gear assembly connected to the rotor; a drive shaft connected to the planetary gear assembly; and a drive shaft support fixed to the valve body, characterized in that... The planetary gear assembly includes: a sun gear, planetary gears meshing with the sun gear, a planetary gear carrier supporting the planetary gears so that they can rotate, and a fixed internal gear meshing with the planetary gears. One of the drive shaft and the drive shaft support has an external thread, and the other has an internal thread for engaging the external thread. When the drive shaft rotates via the planetary gear assembly, the drive shaft moves toward or away from the valve port. The drive shaft support and the fixed internal gear are integrally formed. It also includes a metal component that is pressed into the valve body. The drive shaft support and the fixed internal gear are made of synthetic resin. The drive shaft support, the fixed internal gear, and the metal component are integrally formed.

3. The electric valve according to claim 1 or 2, characterized in that, The planetary gear assembly has N gear sets, each consisting of the sun gear, the planet gears, and the planetary gear carrier, where N is a natural number greater than or equal to 2. The rotor is coaxially connected to the sun gear of the first gear set. The planetary gear carrier of the Kth gear set is coaxially connected to the sun gear of the (K+1)th gear set, where K = 1, ..., N-1. The planetary gear carrier of the Nth gear set is coaxially connected to the drive shaft. The planetary gear assembly has only one fixed internal gear. Each of the N gear sets has a planetary gear that meshes with the fixed internal gear.

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