Electric valve and actuator

Abstract

An electric valve comprising: a planetary gear speed reduction mechanism that reduces and outputs the rotation of a motor and has a carrier which comprises a base and supports a plurality of planet gears on the upper side of the base, said carrier comprising protrusions that protrude further to the outside in the radial direction of the carrier than the planet gears; and a valve body that controls the degree of opening of a valve by means of the output rotation.

Description

Electric valves and actuators

[0001] The present disclosure relates to motorized valves and actuators.

[0002] Conventionally, as disclosed in JP 2021-131160 A, an electric valve that opens and closes a valve via an electric motor is known, in which the input rotation of a rotor is reduced by a planetary gear reduction mechanism and the reduced output rotation is transmitted to a screw mechanism that controls the opening and closing of the valve. Specifically, JP 2021-131160 A discloses a paradox planetary gear type differential gear mechanism. The differential gear mechanism can rotate at a relatively high reduction ratio compared to the fixed gear depending on the difference in the number of teeth between the fixed gear and the output gear.

[0003] The differential gear mechanism uses a cylindrical carrier that rotatably supports multiple planetary gears. The carrier typically has a base on which one axial end of the planetary gears is located, multiple support posts extending from the base toward the opposite side of the valve body, and a plate positioned opposite the other axial end of the planetary gears. The multiple planetary gears are located inside the carrier in the gaps between adjacent support posts.

[0004] In JP 2021-131160 A, an output gear is fitted into a through-hole in the center of a base on the side of the valve body in the axial direction of the carrier. A shaft passing through the central axis of the motor-operated valve is attached to the output gear. Meanwhile, on the side of the carrier opposite the valve body in the axial direction, a sun gear passing through the central axis of the motor-operated valve is inserted into a through-hole in the center of a plate while meshing with the planetary gear. The axis of the carrier is aligned coaxially with the central axis of the motor-operated valve via the planetary gear supported by the carrier, the output gear meshing with the planetary gear, the shaft attached to the output gear, and the sun gear meshing with the planetary gear.

[0005] Patent Document 1: JP 2021-131160 A

[0006] However, in the case of JP 2021-131160 A, during assembly of the motor-operated valve, after the shaft is fitted into the central through-hole of the carrier base, before the sun gear is inserted into the planetary gear through the central through-hole of the plate, the portion of the carrier opposite the base is not connected to the member passing through the central axis. Therefore, for example, during assembly, if the carrier is positioned with the base on the lower side and the plate on the upper side in the vertical direction, the portion of the carrier facing the plate is likely to tilt toward the fixed gear or gear case located radially outside the carrier, with the base as the fulcrum. In other words, until the plate is attached, the upper end of the carrier opposite the base forms the free end, so the area above the carrier's base is displaced radially, and as a result, the carrier axis is likely to tilt relative to the central axis.

[0007] In other words, when the carrier axis is coaxial with the central axis without tilting relative to the central axis, the distance between the tooth tips of the planetary gears located farthest from the center of the carrier and the inner edge of the stationary gear or gear case is approximately constant along the entire circumferential direction when viewed along the axial direction. However, when the carrier axis is tilted relative to the central axis, a portion of the tooth tips of the planetary gears located farthest from the center of the carrier when viewed along the axial direction is closer to the inner edge of the stationary gear or gear case than other portions. This causes unevenness in the distance along the circumferential direction.

[0008] In other words, the state in which the carrier axis is tilted relative to the central axis is created by the portion of the carrier opposite the valve body moving radially outward through the space between the carrier and a member located outside the carrier, such as a fixed gear or a gear case. With the carrier axis tilted, there is a concern that the behavior of the planetary gears will become unstable when rotating after the motor-operated valve is assembled.

[0009] Furthermore, even after the motor-operated valve is assembled and the sun gear and carrier are integrated, the portion of the carrier opposite the valve body may move radially outward through the space between the carrier and a component located outside the carrier when the motor-operated valve is operating. In other words, even if the carrier axis is coaxial with the central axis and not tilted relative to the central axis when the motor-operated valve is assembled, the carrier axis may tilt relative to the central axis when the motor-operated valve is operating after assembly. As a result, there is a concern that the behavior of the planetary gears may become unstable during rotation.

[0010] In view of the above, the present disclosure provides a technique that can suppress carrier tilt.

[0011] The electric valve according to the first aspect of the present disclosure comprises a carrier having a base and supporting a plurality of planetary gears above the base, the carrier having protrusions that protrude radially outward beyond the planetary gears, and a planetary gear reduction mechanism that reduces the rotation of the motor and outputs it, and a valve main body that controls the opening degree of the valve by the rotation of the output.

[0012] In the motor-operated valve according to the first aspect, a protrusion is provided on the carrier, protruding radially outward beyond the planetary gears. Therefore, at the position of the protrusion, the distance between the carrier and a component positioned outside the carrier in the radial direction is shorter by the length of the protrusion than when the protrusion is not provided and the tips of the teeth of the planetary gears are positioned farthest outward from the center of the carrier in the radial direction.

[0013] As a result, even if the axis of the carrier tilts, the distance that the portion of the carrier opposite the valve body moves radially outward in the space between the carrier and a component located outside the carrier, such as the fixed gear or gear case, is shorter than in a case where the protrusion is not provided, thereby reducing the amount of tilt of the carrier.

[0014] In a second aspect, in the motor-operated valve according to the first aspect, the protrusion is disposed at an end of the carrier opposite to the base in the axial direction.

[0015] In the second aspect, the protrusion is disposed at the end of the carrier on the opposite side of the base in the axial direction, which is advantageous in that tilt of the carrier can be suppressed particularly at the portion on the opposite side of the base in the axial direction.

[0016] In a third aspect, in the electric valve according to the first or second aspect, the planetary gear reduction mechanism has a fixed gear that meshes with the planetary gear and an output gear that is provided on the base side of the fixed gear in the axial direction, and the protrusion is arranged between the fixed gear and the output gear.

[0017] In the third aspect, the protrusion is disposed between the fixed gear and the output gear, so that there is no need to change the shape of the portion of the member positioned outside the carrier that faces the protrusion to correspond to the protrusion.

[0018] In a fourth aspect, in the motor-operated valve according to any one of the first to third aspects, the input shaft, output shaft and fixed shaft of the planetary gear reduction mechanism are coaxial with a center axis.

[0019] In the fourth aspect, the input shaft, output shaft, and fixed shaft of the planetary gear reduction mechanism are coaxial with the central axis, thereby realizing a 3K type paradox planetary gear device.

[0020] An actuator according to a fifth aspect of the present disclosure includes a carrier having a base and supporting a plurality of planetary gears on an upper side of the base, the carrier having protrusions that protrude radially outward beyond the planetary gears, and a planetary gear reduction mechanism that decelerates and outputs the rotation of a motor.

[0021] In the actuator according to the fifth aspect, as in the case of the motor-operated valve according to the first aspect, a protrusion that protrudes radially outward beyond the planetary gear is provided on the carrier, so that even if the axis of the carrier is tilted, the amount of tilt of the carrier is reduced compared to when the protrusion is not provided.

[0022] According to the present disclosure, a technique capable of suppressing carrier tilt can be provided.

[0023] FIG. 1 is a cross-sectional view illustrating a motor-operated valve according to an embodiment of the present disclosure, cut along a plane including the central axis which is the rotation axis; FIG. 2 is a perspective view illustrating a carrier of the motor-operated valve according to the embodiment; FIG. 3 is an exploded perspective view illustrating a method of assembling the carrier, fixed gear, and output gear of the motor-operated valve according to the embodiment; FIG. 4 is a perspective view illustrating another example of a carrier of the motor-operated valve according to the embodiment; FIG. 5 is a cross-sectional view illustrating a motor-operated valve according to a first modified example, cut along a plane including the central axis which is the rotation axis; FIG. 6 is a cross-sectional view illustrating a motor-operated valve according to a second modified example, cut along a plane including the central axis which is the rotation axis; FIG. 7 is a cross-sectional view illustrating a motor-operated valve according to a third modified example, cut along a plane including the central axis which is the rotation axis;

[0024] This embodiment will be described below. In the following description of the drawings, identical or similar parts are designated by the same or similar reference numerals. However, the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each device or component, etc. may differ from the actual ones. Therefore, specific thicknesses and dimensions should be determined with reference to the following description. Furthermore, there may be parts with different dimensional relationships and ratios between the drawings. Furthermore, unless otherwise specified in the specification, the number of each component element of the present disclosure is not limited to one, and multiple elements may be present.

[0025] <Configuration of Motor-Operated Valve> The motor-operated valve according to this embodiment has a basic structure including a drive unit, a speed reduction mechanism (i.e., a reduction gear) as a gear reducer unit, a screw mechanism unit, and a valve main body unit. The drive unit functions as an excitation unit and includes a motor consisting of a stator and a rotor. The drive unit includes an electric motor.

[0026] The reduction mechanism performs gear deceleration by receiving a rotational driving force from the drive unit and outputs the decelerated rotation. That is, the input rotation input to the reduction mechanism is the output of the motor of the drive unit. In the reduction mechanism, the input rotation input from the drive unit is decelerated to form an output rotation from the reduction mechanism, and the formed output rotation is output to the screw mechanism. The reduction mechanism includes a planetary gear reduction mechanism (i.e., a planetary gear reduction device).

[0027] The screw mechanism converts the reduced rotation from the reduction mechanism, i.e., the output rotation, into a displacement in the screw axis direction by screw action and outputs it. The valve main body controls the valve aperture by moving the valve element toward and away from the valve seat in response to the displacement output in the screw axis direction of the screw mechanism. In other words, the valve main body controls the valve aperture by the rotation output from the reduction mechanism. Each component of the motor-operated valve 1 according to this embodiment will be described below with reference to FIGS. 1 to 3.

[0028] (Driver Section) As shown in FIG. 1 , the driver section of the motor-operated valve 1 according to this embodiment includes a can 30 , a motor excitation device 2 , and a rotor assembly 50 .

[0029] (Can) The can 30 is a closed-ended cylindrical airtight container fixed to the valve body 10. The can 30 is a closed-ended cylindrical pressure vessel made of a non-magnetic metal material. The lower end of the can 30 in FIG. 1 abuts against the periphery of the receiving member 20 provided on the valve body 10. The can 30 is welded to the receiving member 20, and is fixed to the valve body 10 via the receiving member 20 by welding. The rotor assembly 50 installed inside the can 30 rotates when a drive signal is supplied to the coil 3 of the motor excitation device 2.

[0030] (Motor Exciter) The motor excitation device 2 is attached to the valve body 10 on the outside of the can 30 by a mounting fixture 5, which is screwed to the valve body 10. As shown in Fig. 1, a horizontally extending female thread 10F is provided on the top of the valve body 10, and a through hole 5A is provided in the portion of the mounting fixture 5 that overlaps the valve body 10 in the area where the female thread 10F is provided. A male screw 6 is inserted into the female thread 10F and the through hole 5A, so that the motor excitation device 2 with the can 30 housed inside can be screwed to the valve body 10.

[0031] In the motor excitation device 2, the coil 3 constituting the stator of the motor is molded integrally with resin. The motor excitation device 2 has a resin mold, the coil 3 wound around a bobbin installed inside the resin mold, and a stator that is excited by passing current through the coil 3, and the coil 3 is connected to an external power source via an electric circuit and lead wires (not shown) to receive power. The reference numerals of the resin mold in Fig. 1 have been omitted for clarity.

[0032] (Bearing, Shaft) The bearing 40 has a hat-shaped cross section with a hole 41 in the center (i.e., a cylindrical shape with a flange portion on the outer periphery on the opening side in the axial direction), or a disk shape. The bearing 40 is inserted inside the top of the can 30 and is disposed on the inner surface of the can 30. A shaft 42 is inserted into the hole 41 of the bearing 40. A rotor assembly 50, which is a permanent magnet rotor of the stepping motor, is disposed inside the can 30 so as to be rotatable by the shaft 42.

[0033] (Rotor Assembly) The rotor assembly 50 is rotatably supported within the can 30. The rotor assembly 50 is a permanent magnet type that is rotationally driven by the motor excitation device 2. The motor excitation device 2 is an excitation device for a stepping motor, which is an example of an electric motor. Note that the motor-operated valve of the present disclosure does not necessarily have to include a motor excitation device.

[0034] The rotor assembly 50 is formed in a cylindrical shape with a top from a plastic material containing a magnetic material, and is molded integrally with a sun gear member 54 disposed at the center in the radial direction. In the present disclosure, the members integrally molded from the plastic material may be produced by molding using a mold, or members produced separately may be integrated by fitting, welding, or the like. Alternatively, the members may be integrally molded by, for example, cutting out from a single block of resin material.

[0035] A boss (not shown) extending vertically downward in Fig. 1 is provided at the center in the radial direction of the sun gear member 54. The boss has a through-hole 58 for the shaft 42. A sun gear 56, which is one component of a reduction mechanism 60, is formed on the radially outer side of the boss.

[0036] (Gear Case) The gear case 61 is a cylindrical member. The lower part of the gear case 61 in FIG. 1 is fixed to the upper part of the holder 72. The upper part of the gear case 61 in FIG. 1 is bent toward the fixed gear 62. The gear case 61 is made of metal or the like.

[0037] The bent portion of the gear case 61 comes into contact with the outer surface of the fixed gear 62 made of resin or the like. As shown in Fig. 2, in this embodiment, the fixed gear 62 is fixed to the gear case 61 by caulking. That is, the fixed gear 62 is attached to the gear case 61 at the bent portion of the gear case 61. The gear case 61 houses the reduction mechanism 60. Note that the gear case 61 may be included in the reduction mechanism 60.

[0038] (Operation of Reduction Mechanism) In the reduction mechanism 60, the sun gear 56 of the rotor assembly 50 functions as an input gear. The planetary gears 65 supported by the carrier 64 mesh with the sun gear 56, and also mesh with the fixed gear 62 (more precisely, a ring gear 62A1 which is a fixed-side internal gear formed on the inner peripheral surface of the fixed gear 62 in FIG. 3 ) and the output gear 66 (more precisely, an output-side internal gear 66D formed on the inner peripheral surface of the output gear 66 in FIG. 3 ). The entire carrier 64 is supported so as to be able to rotate freely on the output gear 66.

[0039] The ring gear 62A1 and the output-side internal gear 66D have different numbers of teeth, but are both configured to mesh with the three planetary gears 65. To achieve this meshing, the addendum shift coefficients of the ring gear 62A1 and the output-side internal gear 66D are set to appropriate values. When the planetary gears 65 rotate and revolve while meshing with the ring gear 62A1 of the fixed gear 62, the output gear 66 rotates relative to the fixed gear 62 due to the difference in the number of teeth.

[0040] Therefore, in the reduction mechanism 60, the input rotation from the sun gear 56 is reduced and output to the output gear 66, resulting in a large reduction ratio of, for example, about 50:1. As a result, the rotation speed of the rotor assembly 50 is reduced, for example, to 1 / 50, and transmitted to the screw shaft 71 via the output shaft 70. As a result, the screw shaft 71 can rotate at a very small rotation speed. This allows the valve opening to be controlled with high resolution.

[0041] (Actuator) As shown in Figure 1, the motor-operated valve 1 of this embodiment is configured with an actuator AC used to control the opening and closing of the valve. The actuator AC includes a speed reduction mechanism 60. The actuator AC is a component of the motor-operated valve 1 and is connected to the valve main body VB. The actuator AC may include one or more of a gear case 61, a fixed gear 62, a carrier 64, a planetary gear 65, and an output gear 66.

[0042] (Output Shaft) As shown in Fig. 1, the output shaft 70 is a member having a cylindrical portion 70C that is the main body, a first hole 70A with a bottom formed in the upper part of the cylindrical portion 70C in Fig. 1 for receiving the shaft 42, and a second hole 70B formed in the cylindrical portion 70C on the opposite side of the first hole 70A. The second hole 70B is, for example, a slot or a slit-like groove. As shown in Fig. 1, the flat protrusion 71A of the threaded shaft 71 is inserted into the second hole 70B, whereby the rotation of the output shaft 70 is transmitted to the shaft 42.

[0043] (Piping and Holder) Corresponding refrigerant pipes are attached airtight or liquidtight to the first opening 10A and the second opening 10B of the valve body 10. A holder 72 is provided on the upper side of the valve body 10 in FIG.

[0044] The holder 72 is a cylindrical member. The outer diameter of the holder 72 is smaller than the outer diameter of the valve body 10. The outer edge of the valve body 10 is located radially outward from the outer edge of the holder 72. A shoulder of the valve body 10 is formed at the boundary height between the valve body 10 and the holder 72. The valve body 10 and the holder 72 are manufactured separately using different materials and then integrated together. A ring-shaped receiving member 20 is welded to the outer peripheral surface of the holder 72.

[0045] With the bearing 73 fitted inside the holder 72, the holder 72 and the bearing 73 are integrated by press-fitting, caulking, or the like. A gear case 61 is attached in a fitted state to the upper side of the holder 72 in FIG. 1. A protrusion 71A is provided on the upper part of the screw shaft 71 in FIG. 1. The protrusion 71A is inserted into a second hole 70B of the output shaft 70 of the reduction mechanism 60. A ball 74 is fixed to a hole 71B in the lower part of the screw shaft 71 in FIG. 1. Rotation of the screw shaft 71 is converted into movement along the screw axis direction, which is parallel to the central axis X in FIG. 1, and is transmitted to the valve stem 75 via the ball 74. The central axis X is the central axis of the valve main body VB and also the central axis of the motor-operated valve 1.

[0046] (Screw mechanism) The screw mechanism of the motor-operated valve 1 uses a feed screw mechanism to convert the rotation of the output shaft 70 of the reduction mechanism 60 into linear motion that moves the valve element 76 toward and away from the valve seat 17, and transmits this to the valve stem 75. The screw mechanism of this embodiment includes a screw shaft 71. The screw shaft 71 is threadedly coupled to threads formed on the inner surface of a cylindrical bearing 73. The screw mechanism drives the screw shaft 71. Note that in the present disclosure, the bearing may be formed integrally with the holder using the same member. When the bearing and holder are formed integrally, the output gear 66 and the output shaft 70 are directly supported by the holder.

[0047] 1 , the valve body VB of this embodiment includes a screw shaft 71, a ball 74, a ball receiving member 74A, a valve stem 75, and a valve element 76. The valve body VB may also include a valve body 10, a valve chamber 12, and an orifice 14.

[0048] In the valve body VB of the motor-operated valve 1, the movement of the screw shaft 71 is transmitted to the valve stem 75 via the ball 74 and the ball receiving member 74A, and as a result, the valve element 76 attached to the tip of the valve stem 75 moves linearly in the vertical direction in Figure 1 (the direction in which the central axis X extends). Therefore, the flow path area between the valve element 76 and the orifice 14 is controlled, and as a result, the flow rate of the refrigerant is adjusted.

[0049] In addition, a spring bearing member 26 is disposed between the valve stem 75 and the valve body 10. As will be described later, the spring bearing member 26 has the function of supporting the lower end of the compression coil spring 24 that urges the valve element 76 upward, and the function of acting as a sliding guide when the valve element 76 moves up and down.

[0050] (Valve Body) As shown in FIG. 1 , the valve body 10 has a valve chamber 12 formed in the lower part and an orifice 14 extending downward from the bottom of the valve chamber 12. The valve body 10 has a first opening 10A and a second opening 10B. The valve body 10 is a valve body. The valve body 10 can be made of a metal material such as aluminum, stainless steel, or brass. Inside the valve body 10, between the first opening 10A and the second opening 10B, there is provided a valve chamber 12 that communicates with both the first opening 10A and the second opening 10B.

[0051] A refrigerant pipe inserted into the first opening 10A and communicating with the side surface of the valve chamber 12, and a refrigerant pipe inserted into the second opening 10B and communicating with the lower end of the orifice 14 are attached airtight or liquidtight to the valve body 10. The illustration of each refrigerant pipe is omitted. The motor-operated valve 1 controls the opening and closing of the fluid flow between the first opening 10A and the second opening 10B.

[0052] The upper portion of the valve body 10 in Fig. 1 is provided with a first diameter portion 10C that opens upward and extends in the vertical direction, and a second diameter portion 10D that is continuous with the first diameter portion 10C and also extends in the vertical direction. The second diameter portion 10D is located between the first opening 10A and the second opening 10B in Fig. 1 and communicates with both the first opening 10A and the second opening 10B. The second diameter portion 10D has a smaller diameter than the first diameter portion 10C. A spring bearing member 26 is disposed at the transitional step between the first diameter portion 10C and the second diameter portion 10D.

[0053] A holder 72 with a valve element 76 disposed therein is inserted into the inside of the first diameter portion 10C. The holder 72 is attached to the valve body 10 by fitting, screwing, or the like. In FIG. 1, the valve element 76 protrudes downward from the holder 72 and passes through the spring receiving member 26. In FIG. 1, the lower end of the valve element 76 that passes through the spring receiving member 26 is located in the valve chamber 12 inside the second diameter portion 10D. The valve chamber 12 is formed between the spring receiving member 26 and the seat 10E in the second diameter portion 10D.

[0054] The seat 10E is disposed below the second diameter portion 10D in Fig. 1. The seat 10E is made of, for example, metal. The inner peripheral surface of the seat 10E is formed as an orifice 14 that communicates with the valve chamber 12. A valve seat 17 is formed at the open end of the seat 10E as part of the wall surface that forms the valve chamber 12.

[0055] (Valve Disk, Valve Stem) A valve disk 76 is disposed inside the valve chamber 12. The valve disk 76 moves toward and away from the valve seat 17 to open and close an opening formed in the valve seat 17. That is, the valve disk 76 is capable of opening and closing the opening of the valve seat 17. In order to move the valve disk 76, a valve stem 75 linked to the screw shaft 71 of the screw mechanism is connected to the valve disk 76. The valve disk 76 is supported inside the valve chamber 12 of the valve body 10 so as to be slidable along the central axis X.

[0056] 1, the spring receiving member 26 has a small diameter portion 26A, a large diameter portion 26B located above the small diameter portion 26A and having a larger diameter than the small diameter portion 26A, and a flange-shaped portion 26C extending horizontally from the upper edge of the large diameter portion 26B. A step portion 26D is formed at the boundary between the large diameter portion 26B and the flange-shaped portion 26C.

[0057] The small diameter portion 26A is disposed inside the valve chamber 12. The outer surface of the large diameter portion 26B contacts the inner surface of the second diameter portion 10D of the valve body 10. The lower surface of the flange portion 26C in FIG. 1 contacts the step at the boundary between the first diameter portion 10C and the second diameter portion 10D of the valve body 10 inside the valve body 10. A valve stem 75 is slidably inserted inside the spring bearing member 26.

[0058] As shown in Fig. 1 , the side surface of the axial center of the valve stem 75 contacts the inner surfaces of the small diameter portion 26A and the large diameter portion 26B of the spring receiving member 26. A compression coil spring 24 is disposed between the outer surface of the upper spring receiving portion 75A of the valve stem 75 and the inner surface of the lower portion of the holder 72, and between the outer surface of the upper portion of the valve stem 75 and the inner surface of the flange-shaped portion 26C of the spring receiving member 26. The lower winding end of the compression coil spring 24 in Fig. 1 contacts the upper surface of the step portion 26D at the boundary between the large diameter portion 26B and the flange-shaped portion 26C. The upper winding end of the compression coil spring 24 in Fig. 1 contacts the flange-shaped spring receiving portion 75A provided on the upper portion of the valve stem 75.

[0059] 1, a ball receiving member 74A of a ball 74 is fixed to the upper end of the valve stem 75 in a state where it is inserted inside a spring receiving portion 75A. As shown in FIG. 1, the screw shaft 71 abuts against the upper portion of the ball 74. The ball 74 transmits axial thrust to the valve stem 75 side by the screw mechanism.

[0060] 1 illustrates a state in which the valve stem 75 descends due to the output rotation from the speed reduction mechanism 60 and the valve element 76 reaches its lowest point, thereby closing the motor-operated valve 1. On the other hand, when the output rotation is reversed from the state illustrated in FIG. 1, the valve stem 75 ascends due to the biasing force of the compression coil spring 24, and as a result, the motor-operated valve 1 opens.

[0061] (Paranormal Planetary Gear Reduction Mechanism) The reduction mechanism 60 according to this embodiment is a paranormal planetary gear reduction mechanism. That is, in this embodiment, the input shaft, output shaft, and fixed shaft of the reduction mechanism 60 are coaxial with the central axis X. In other words, the input shaft, output shaft, and fixed shaft of the reduction mechanism 60 have the same rotational axis. The reduction mechanism 60 is a 3K-type paradox planetary gear device.

[0062] In the present disclosure, the input shaft, output shaft, and fixed shaft of the planetary gear reduction mechanism do not necessarily have to be coaxial with the central axis. Any of the input shaft, output shaft, and fixed shaft may have a rotational axis different from the central axis. In the present disclosure, the reduction mechanism is not limited to a paradox planetary gear reduction mechanism, and may be another planetary gear reduction mechanism (i.e., a planetary gear reduction device).

[0063] 1, in this embodiment, the reduction mechanism 60 can be divided into an upper input region and a lower output region along the axial direction. As shown in FIG. 1, the sun gear 56, the upper parts of the three planetary gears 65, and the fixed gear 62 are arranged in the input region, and the lower parts of the three planetary gears 65 and the output gear 66 are arranged in the output region.

[0064] In the input region, the input rotation from the motor excitation device 2 is input to the sun gear 56, which meshes with the teeth of each of the three planetary gears 65. In the output region, the output rotation is output to the output shaft 70 from the output gear 66, which meshes with the teeth of each of the three planetary gears 65.

[0065] (Fixed Gear) The fixed gear 62 is provided in the reduction mechanism 60. The fixed gear 62 has a ring-shaped main body 62A made by molding, for example, resin. As shown in Fig. 2, a ring gear 62A1 is formed on the inner periphery of the main body 62A of the fixed gear 62. The fixed gear 62 meshes with the planetary gears.

[0066] A through-hole 62A2 is formed in the radial center of the ring-shaped main body 62A. As shown in Fig. 2, a flange 62B is formed on the outer periphery of the upper part of the fixed gear 62, and holes 62B1 and protrusions 62B2 for fixing the fixed gear 62 to the upper part of the gear case 61 are formed alternately in the circumferential direction. As shown in Fig. 2, a ring-shaped facing region 62C that protrudes above the ring gear 62A1 is provided on the upper part of the fixed gear 62. The facing region 62C has an inner circumferential surface 62C1.

[0067] The fixed gear 62 has a number of teeth different from the number of teeth of the output gear 66. In this embodiment, the root diameter of the fixed gear 62 is, for example, 15 mm or less. However, in the present disclosure, the root diameter of the fixed gear 62 is not limited to this and can be set arbitrarily.

[0068] (Sun Gear) As shown in Fig. 1, the sun gear 56 is disposed concentrically with the fixed gear 62. Input rotation is input to the sun gear 56. The sun gear 56 meshes with the upper teeth of the planetary gear 65 in Fig. 1.

[0069] (Output Gear) As shown in FIG. 3 , the output gear 66 is a cylindrical member with a bottom, including a bottom 66A and a wall 66B rising from the periphery of the bottom 66A. A hole (see, for example, hole 66C in FIG. 1 ) is formed at the center of the bottom 66A in the radial direction, into which the cylindrical portion 70C of the output shaft 70 is press-fitted. An output-side internal gear 66D is formed on the inner periphery of the output gear 66, thereby forming a ring gear. The output gear 66 is provided in the output region and meshes with the lower teeth of the planetary gears 65 of the carrier 64 located at the top in FIG. 3 . The output gear 66 is provided closer to the base than the fixed gear 62 in the axial direction (i.e., the vertical direction in FIG. 1 ).

[0070] (Planetary Gear) As shown in Fig. 2, the planetary gear 65 is a cylindrical member. Teeth are provided on the outer periphery of the planetary gear 65 as a gear portion. Note that, although the present embodiment has been described as an example in which the number of planetary gears is three, the present disclosure is not limited to this. The number of planetary gears may be any natural number equal to or greater than two.

[0071] During assembly, one end face side (i.e., the lower end face side in FIG. 1) of the three planetary gears 65 faces the base 64A of the carrier 64, and a plate 64C is attached onto the other end face (i.e., the upper end face side in FIG. 1) of the three planetary gears 65, thereby integrating the three planetary gears 65 and the carrier 64.

[0072] (Carrier) The carrier 64 is formed by molding a resin such as plastic. The carrier 64 constitutes the reduction mechanism 60. As shown in FIG. 1, the carrier 64 has a base 64A having an axial hole 64A1 through which the shaft 42 passes in its radial center. The base 64A is a disk-shaped member. As shown in FIG. 2, the base 64A is the bottom of the carrier 64. The carrier 64 has a washer-shaped plate 64C. The plate 64C is the top of the carrier 64. The plate 64C has an axial hole 64C1 through which the shaft 42 passes in its radial center.

[0073] 2, a protrusion 64B1 protruding upward from the top surface is provided on the top surface of each of the three support columns 64B. Furthermore, through holes 64C2 corresponding to the three protrusions 64B1 are provided in the plate 64C.

[0074] As shown in FIG. 3 , three support columns 64B extending upward are erected at the periphery of the upper surface of the base 64A with a gap G in the circumferential direction. All three support columns 64B are rod-shaped. Note that in the present disclosure, the number of support columns is not limited to three, as long as there is more than one. Also, although the three support columns 64B have the same shape in the present embodiment, the present disclosure is not limited to this, and each of the support columns may have a different shape.

[0075] Three planetary gears 65 are arranged upright in three gaps G formed between adjacent pairs of the three support columns 64B. With the planetary gears 65 arranged inside the carrier 64, one plate 64C is placed on top of the three support columns 64B. Furthermore, the support columns 64B and the plate 64C are integrated by fixing the protrusions 64B1 of the support columns 64B into the through holes 64C2 of the plate 64C by press-fitting or caulking.

[0076] Each of the three planetary gears 65 is rotatable while being sandwiched between a lower base 64A and an upper plate 64C in Fig. 2. The carrier 64 rotatably supports each of the three planetary gears 65 between three support columns 64B above the base 64A in Fig. 2.

[0077] (Protrusion) Next, the protrusion 64D of the carrier 64 according to this embodiment will be specifically described with reference to Figures 1 and 2. As shown in Figure 2, in this embodiment, the carrier 64 is provided with the protrusion 64D.

[0078] In this embodiment, the protrusion 64D is disposed at the upper end in the axial direction of the carrier 64 in FIG. 2 , i.e., at the end opposite the valve body in the axial direction, facing the inner circumferential surface 62C1 of the facing region 62C of the fixed gear 62. In this embodiment, the axial direction is the direction in which the central axis X extends. Note that, in this disclosure, it is not essential that the protrusion be disposed at the upper end of the carrier. In this disclosure, the position of the protrusion in the axial direction of the carrier 64 can be changed as desired.

[0079] 1 and 2, the protrusion 64D protrudes outward from the central axis X in the radial direction (left-right direction in FIG. 1) of the carrier 64 beyond the planet gear 65. As shown in FIG. 2, the distance in the circumferential direction between the protrusion 64D of the carrier 64 and the inner circumferential surface 62C1 of the facing region 62C is shorter than the distance between the outer circumferential surface of the carrier 64 in a portion where the protrusion 64D is not provided and the inner circumferential surface 62C1 of the facing region 62C.

[0080] As shown in FIG. 2 , the protrusion 64D in this embodiment is a plate-shaped member. In this embodiment, the main surface of the plate-shaped protrusion 64D is rectangular when viewed from the front (i.e., when viewed along the radial direction of the carrier 64). In the present disclosure, the shape of the main surface of the protrusion in the front view is not limited to this and may be any geometric shape, such as triangular or elliptical. Furthermore, a partial notch or a protrusion may be formed on the main surface of the protrusion. Furthermore, the protrusion may be divided into two by forming a slit extending in the up-down direction in FIG. 2 (i.e., a gap in the circumferential direction).

[0081] 2, in this embodiment, the main surface of the plate-shaped protrusion 64D is curved in an arc shape when viewed in a plan view along the axial direction. In other words, the central portion of the main surface of the plate-shaped protrusion 64D in a plan view protrudes outward from both ends of the main surface in the circumferential direction. In the present disclosure, the shape of the main surface of the protrusion in a plan view is not limited to this and can be designed as desired, such as a U-shape or a V-shape.

[0082] In this embodiment, the protrusion 64D is molded integrally with the base 64A and the support 64B by resin molding. In this disclosure, the protrusion may be made of any material. Also, in this disclosure, for example, the protrusion may be made separately from the support and then joined to the support, thereby integrating the protrusion and the support.

[0083] In this embodiment, the protrusion 64D connects a pair of circumferentially adjacent columns 64B to each other. Note that in the present disclosure, it is not essential that the protrusion connects adjacent columns to each other. The protrusion may be provided on only one of the adjacent columns, for example, like a cantilever beam.

[0084] In addition, although the present embodiment illustrates a case in which the upper and lower edges of the protrusion 64D in Fig. 2 extend parallel to each other in the circumferential direction of the carrier 64, the present disclosure is not limited to this. The upper and lower edges of the protrusion may be formed so that their vertical widths become narrower, for example, from the top to the bottom in Fig. 2 or from the bottom to the top in Fig. 2. In other words, the upper and lower edges of the protrusion may extend circumferentially such that an imaginary extension line of the upper edge of the fence portion in Fig. 2 intersects with an imaginary extension line of the lower edge as the fence portion approaches from one support post side to the other support post side.

[0085] The protrusions 64D function as outer covers for the planetary gears 65. In this embodiment, the protrusions 64D are arranged outside the three planetary gears 65 in the radial direction of the carrier 64 and facing the respective planetary gears 65.

[0086] In the present disclosure, the number of planetary gears 65 that the protrusion 64D is arranged to face may be one, or may be any number of two or more. That is, the protrusion 64D may be provided to face all of the plurality of planetary gears 65 arranged inside one carrier 64, or may be arranged to face some of the plurality of planetary gears 65. In the present disclosure, it is sufficient that the protrusion is arranged to face the planetary gear on the outer side of one or more planetary gears in the radial direction of the carrier.

[0087] The protrusion 64D overlaps with the gap G between adjacent support columns 64B in the radial direction of the carrier 64. In the present embodiment, the case where the protrusion 64D overlaps with one gap G in the radial direction of the carrier 64 is formed over the entire circumferential direction of the one gap G has been exemplified, but the present disclosure is not limited to this. In the present disclosure, the protrusion may overlap with, for example, a portion of one gap G in the circumferential direction.

[0088] (Method of assembling the motor-operated valve) Next, a method of assembling the motor-operated valve 1 according to this embodiment will be described with reference to Figures 1 to 3. First, the carrier 64 and the planetary gears 65 are integrated together. Specifically, first, on the upper surface of the base 64A of the carrier 64 without the plate 64C attached, the three planetary gears 65 are arranged upright in three gaps G formed between pairs of adjacent support columns 64B.

[0089] 3, a plate 64C is placed on top of the carrier 64 with three planetary gears 65 arranged upright inside. The support posts 64B of the carrier 64 are fitted into the plate 64C, and as a result, the carrier 64 and the planetary gears 65 are integrated.

[0090] 3, the fixed gear 62 with the gear case 61 attached is inserted from above into the output gear 66, which is located below in the vertical direction, so that the fixed gear 62 is positioned above the output gear 66. Next, the carrier 64, which is integrated with the planetary gears 65, is inserted into the inside of the output gear 66 through a through-hole 62A2 formed in the main body 62A1 above the fixed gear 62. As shown in FIG. 2, the protrusion 64D of the inserted carrier 64 faces the inner circumferential surface 62C1 of the facing region 62C of the carrier 64.

[0091] 1, the lower teeth of the planetary gears 65 supported by the carrier 64 mesh with the output-side internal gear 66D on the inside of the output gear 66. Also, the upper teeth of the planetary gears 65 supported by the carrier 64 mesh with the ring gear 62A1 on the inside of the fixed gear 62. The positions of the three planetary gears 65 inside the carrier 64 are determined by the meshing between the sun gear 56 and the three planetary gears 65.

[0092] (Other examples of protrusions) In this embodiment, an example is given in which three protrusions 64D are arranged intermittently in the circumferential direction so that the protrusions 64D overlap with the gap G in the radial direction, as in the protrusion 64D in Figure 3, but in the present disclosure, the configuration of the protrusions is not limited to this.

[0093] In the present disclosure, for example, as shown in Fig. 4, one protrusion 64D3 may be formed in a ring shape extending over the entire circumferential direction. By forming the protrusions 64D3 over the entire circumferential direction, the range in which tilt can be suppressed is expanded compared to when the protrusions 64D3 are arranged intermittently in the circumferential direction. Note that the present disclosure does not exclude, for example, a protrusion provided on the surface of one or more support columns 64B without overlapping with the gap G in the radial direction.

[0094] (Operation and Effect) In the motor-operated valve 1 according to this embodiment, the carrier 64 is provided with a protrusion 64D that protrudes radially outward beyond the planetary gear 65. Therefore, at the position of the protrusion 64D, the distance between the carrier 64 and the fixed gear 62 located outside the carrier 64 in the radial direction is shorter by the length of the protrusion 64D compared to when the protrusion 64D is not provided and the tooth tips of the planetary gears 65 are located at the outermost position from the center of the carrier 64 in the radial direction.

[0095] As a result, even if the axis of the carrier 64 tilts, the distance that the portion of the carrier 64 opposite the valve body VB moves radially outward in the space between the carrier 64 and the fixed gear 62 is shorter than when the protrusion 64D is not provided. Therefore, the amount of tilt of the carrier 64 is reduced, and tilt of the axis of the carrier 64 can be suppressed. In this embodiment, when the motor-operated valve 1 rotates, the protrusion 64D rotates while contacting the inner circumferential surface 62C1 of the opposing region 62C of the fixed gear 62. In other words, the protrusion 64D slides. As a result, the stability of the behavior of the planetary gear 65 during rotation is improved.

[0096] Furthermore, when assembling the motor-operated valve 1, the amount of tilt of the carrier 64 is reduced by contact with the inner circumferential surface 62C1 of the opposing region 62C of the fixed gear 62, thereby suppressing tilt of the axis of the carrier 64. Similarly, in the actuator AC according to this embodiment, tilt of the axis of the carrier 64 can be suppressed.

[0097] In the present disclosure, when the motor-operated valve 1 rotates, it is not essential that the protrusion 64D contact the inner circumferential surface 62C1 of the opposing region 62C of the fixed gear 62. In addition, in the present disclosure, when the motor-operated valve 1 is assembled, it is not essential that the protrusion 64D contact the inner circumferential surface 62C1 of the opposing region 62C of the fixed gear 62.

[0098] Furthermore, in this embodiment, the protrusions 64D are provided at the positions of the gaps G between pairs of adjacent columns 64B. Therefore, when assembling the motor-operated valve 1, when the three planetary gears 65 are arranged upright between pairs of adjacent columns 64B on the upper surface of the base 64A of the carrier 64 without the plate 64C attached, the protrusions 64D can prevent the three planetary gears 65 from tipping over through the gaps G toward the outside of the carrier 64. That is, the protrusions 64D in this embodiment can function as a member that guides the planetary gears 65 so that they stand along the central axis X without tipping over.

[0099] In this embodiment, the protrusion 64D is disposed at the end of the carrier 64 opposite the base 64A in the axial direction, i.e., at the upper end of the carrier 64 in Fig. 1 which forms a free end until the plate 64C is attached. This is particularly advantageous in that tilting of the carrier 64 can be suppressed by suppressing radial displacement of the upper end of the carrier 64 in Fig. 1.

[0100] In this embodiment, the input shaft, output shaft, and fixed shaft of the planetary gear reduction mechanism are coaxial with the central axis, thereby realizing a 3K type paradox planetary gear device.

[0101] (First Modification: Plate as Protrusion) As shown in Fig. 5, in the motor-operated valve 1A according to the first modification, the outer periphery of the ring-shaped plate 64CA functions as a protrusion that protrudes radially outward beyond the planetary gear 65. In the first modification, the ring-shaped opposing region 62C that protrudes above the ring gear 62A1 at the top of the fixed gear 62 in Fig. 5 is formed up to the height of the plate 64CA. The outer periphery of the plate 64CA faces the inner periphery 62C1 of the opposing region 62C.

[0102] In this embodiment, the plate 64CA has a ring-shaped portion that protrudes radially outward beyond the planetary gear 65 and extends over the entire circumferential direction. Note that in the present disclosure, one or more portions that protrude radially outward beyond the planetary gear 65 may be provided on the outer periphery of the plate so as to be arranged intermittently in the circumferential direction. The configuration of the motor-operated valve 1A according to the first modification, other than the plate 64CA and the opposing region 62C of the fixed gear 62, is the same as the configuration of the motor-operated valve 1 according to this embodiment, and therefore a repeated description will be omitted.

[0103] (Operation and Effect of the First Modification) In the motor-operated valve 1A according to the first modification, the outer periphery of the plate 64CA also functions as a protrusion that protrudes radially outward beyond the planetary gear 65. Therefore, similar to the present embodiment, tilt of the axis of the carrier 64 can be suppressed.

[0104] Furthermore, in the first modified example, the protrusion can be formed simply by enlarging the shape of the ring-shaped plate 64CA. Therefore, the protrusion can be fabricated more easily than when, for example, the curved protrusion 64D illustrated in Figure 2 is provided on the carrier 64. Other effects of the first modified example are the same as those of the present embodiment.

[0105] (Second variant: protrusion located at the lower end of the fixed gear) As shown in Figure 6, in the electric valve 1B of the second variant, a protrusion 64D that protrudes radially outward beyond the planetary gear 65 is provided in a position facing the inner surface 62C1 of the opposing area 62C at the lower end of the fixed gear 62.

[0106] 6, in the second modified example, the ring-shaped facing region 62C is formed below the ring gear 62A1 in the lower part of the fixed gear 62. The protrusion 64D faces the inner circumferential surface 62C1 of the facing region 62C. In other words, in the second modified example, the facing region 62C is formed so that the lower part of the internal space of the fixed gear 62 has a larger diameter in the radial direction than the upper part.

[0107] As in the second modification, in the present disclosure, the axial position of the protrusion 64D can be set arbitrarily. The configuration of the motor-operated valve 1B according to the second modification, other than the protrusion 64D and the facing region 62C of the fixed gear 62, is the same as the configuration of the motor-operated valve 1 according to the present embodiment, and therefore, a duplicated description will be omitted.

[0108] (Operation and Effect of the Second Modification) In the motor-operated valve 1B according to the second modification, the carrier 64 is also provided with the protrusion 64D that protrudes outward beyond the planetary gear 65. Therefore, as in the present embodiment, the tilt of the axis of the carrier 64 can be suppressed.

[0109] In the second modified example, the protrusion 64D is provided at a position facing the inner circumferential surface 62C1 of the facing region 62C at the lower end of the fixed gear 62 in Fig. 6. Therefore, there is no need to form a portion that protrudes above the ring gear 62A1, as in the facing region 62C at the upper part of the fixed gear 62 in Fig. 2. Other effects of the second modified example are similar to those of the present embodiment.

[0110] (Third Modification: Protrusion Arranged Opposite to Gear Case) As shown in Fig. 7 , in the motor-operated valve 1C according to the third modification, a space capable of accommodating the protrusion 64D is formed between the fixed gear 62 and the output gear 66 in the axial direction (i.e., the up-and-down direction in Fig. 7 ). The protrusion 64D is arranged in the space between the fixed gear 62 and the output gear 66.

[0111] In the third modified example, the protrusion 64D faces the inner circumferential surface of the gear case 61. That is, in the third modified example, the gear case 61 has a facing region 61C with an inner circumferential surface facing the protrusion 64D. The configuration of the motor-operated valve 1C according to the third modified example, other than the protrusion 64D and the facing region 61C of the gear case 61, is the same as the configuration of the motor-operated valve 1 according to the present embodiment, and therefore, a duplicated description will be omitted.

[0112] (Effects of the Third Modification) In the motor-operated valve 1C according to the third modification, the carrier 64 is also provided with a protrusion 64D that protrudes outward beyond the planetary gear 65. Therefore, as in the present embodiment, tilting of the axis of the carrier 64 can be suppressed. In the third modification, when the motor-operated valve 1C rotates, the protrusion 64D rotates while contacting the opposing region 61C of the gear case 61. In other words, the protrusion 64D slides. As a result, the stability of the behavior of the planetary gear 65 during rotation is improved.

[0113] Furthermore, when assembling the motor-operated valve 1C, the amount of tilt of the carrier 64 is reduced by contacting the opposing region 61C of the gear case 61, thereby suppressing tilt of the axis of the carrier 64. Note that, in the present disclosure, when the motor-operated valve 1C rotates, it is not essential that the protrusion 64D contact the opposing region 61C of the gear case 61. Also, in the present disclosure, when assembling the motor-operated valve 1C, it is not essential that the protrusion 64D contact the opposing region 61C of the gear case 61.

[0114] Furthermore, in the third modified example, the protrusion 64D is disposed in the space between the fixed gear 62 and the output gear 66 in the radial direction. Therefore, like the inner circumferential surface 62C1 of the facing region 62C of the fixed gear 62D in FIG. 2 , for example, in the gear case 61, which is a member located outside the carrier 64, the shape of the facing region 61C facing the protrusion 64D does not need to be changed to correspond to the protrusion 64D. Other effects of the third modified example are similar to those of the present embodiment.

[0115] Although the present disclosure has been described based on the above disclosed embodiments, the descriptions and drawings that form part of this disclosure should not be understood to limit the present disclosure. For example, the present disclosure can be configured by partially combining the configurations illustrated in the attached drawings. The present disclosure includes various embodiments not described above, and the technical scope of the present disclosure is defined only by the invention-specific matters in the scope of the claims that are appropriate from the above description.

[0116] The disclosure of Japanese Patent Application No. 2023-223592, filed on December 28, 2023, is incorporated herein by reference in its entirety. In addition, all documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A planetary gear type reduction mechanism having a base and a carrier that supports a plurality of planetary gears above the base, the carrier having a protruding portion that protrudes outward of the planetary gears in the radial direction of the carrier, the planetary gear type reduction mechanism reducing the rotation of a motor and outputting the reduced rotation; and a valve body portion that controls the opening degree of a valve by the rotation of the output. An electric valve comprising the above components.

2. The electric valve according to claim 1, wherein the protruding portion is disposed at an end portion of the carrier on the side opposite to the base in the axial direction of the carrier.

3. The planetary gear type reduction mechanism has a fixed gear that meshes with the planetary gear, and an output gear provided on the side of the base rather than the fixed gear in the axial direction. The electric valve according to claim 1 or 2, wherein the protruding portion is disposed between the fixed gear and the output gear.

4. The electric valve according to any one of claims 1 or 2, wherein the input shaft, output shaft, and fixed shaft of the planetary gear type reduction mechanism are coaxial with the central axis.

5. An actuator having a base and a carrier that supports a plurality of planetary gears above the base, the carrier having a protruding portion that protrudes outward of the planetary gears in the radial direction of the carrier, the actuator comprising a planetary gear type reduction mechanism that reduces the rotation of a motor and outputs the reduced rotation.

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