Electric valve and actuator

Abstract

An electric valve according to the present invention comprises: a planetary gear speed reduction mechanism that reduces and outputs the rotation of a motor; and valve body that controls the degree of opening of a valve by means of the output rotation. The planetary gear speed reduction mechanism has a carrier which comprises a base and a plurality of support columns erected on the base at intervals along the circumferential direction, and supports a plurality of planet gears between the plurality of support columns on the upper side of the base, said carrier having a rail that is positioned to the outside of at least one planet gear in the radial direction of the carrier and overlaps a gap in the radial direction.

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] One axial end face (for example, an upper end face) and the other axial end face (for example, a lower end face) of the planetary gear are each formed with a fitting protrusion such as a pin or protrusion, or a fitting hole such as a recess or a through hole. Meanwhile, fitting holes or fitting protrusions corresponding to the shapes of the fitting protrusions or fitting holes of the planetary gear are formed in the base and plate of the carrier. JP 2021-131160 A exemplifies protrusions formed on both axial end faces of the planetary gear as fitting protrusions, and through holes formed in the base and the plate as fitting holes.

[0005] The mating projections and mating holes form a mating structure between the planetary gears and the carrier. During assembly of the motor-operated valve, even when the planetary gears are attached to the base only at their lower end faces and are not supported by other members at their upper end faces before the plate is attached, the mating structure on the lower end face prevents the planetary gears from tipping outward from the carrier through the gaps between adjacent supports.

[0006] Patent Document 1: JP 2021-131160 A

[0007] Here, as the motor-operated valve becomes smaller, there is a need to reduce the size of the carrier that supports the planetary gear. When the carrier is required to be smaller, the diameters of the mating protrusions and mating holes must also be reduced accordingly. However, if the carrier itself is a relatively small component, the mating protrusions and mating holes are also very small. For this reason, in the case of JP 2021-131160 A, when trying to reduce the size of the carrier, it is difficult to form the mating protrusions and mating holes with high precision. As a result, it is difficult to promote the miniaturization of the carrier.

[0008] In view of the above, the present disclosure provides a technique that facilitates the promotion of carrier miniaturization.

[0009] The electric valve according to the first aspect of the present disclosure comprises a carrier having a base and a plurality of pillars erected on the base with gaps in the circumferential direction, the carrier supporting a plurality of planetary gears between the plurality of pillars above the base, the carrier having a fence portion that is arranged radially outside one or more of the planetary gears of the carrier and overlaps with the gaps in the radial direction, and the carrier comprises a planetary gear reduction mechanism that reduces the rotation of the motor and outputs it, and a valve main body portion that controls the opening degree of the valve by the rotation of the output.

[0010] In the motor-operated valve according to the first aspect, the carrier is provided with a barrier portion that is disposed radially outside one or more planetary gears and overlaps with a gap between adjacent support posts. Therefore, during assembly, when the planetary gears are disposed between the support posts above the base inside the carrier, the barrier portion can prevent the planetary gears from tipping outward from the carrier, regardless of whether or not there is a mating structure between the planetary gears and the carrier. In other words, even if the carrier is miniaturized, the planetary gears can be stably disposed inside the carrier during assembly of the motor-operated valve.

[0011] In a second aspect, in the motor-operated valve according to the first aspect, the fence portion connects a pair of the support pillars adjacent to each other in the circumferential direction.

[0012] In the second aspect, the fence portion connects a pair of adjacent support posts in the circumferential direction, thereby improving the strength of the carrier.

[0013] In a third aspect, in the electric valve according to the first or second aspect, the planetary gear reduction mechanism has a fixed gear, and the fence portion is arranged opposite the fixed gear at the end of the carrier opposite the valve main body portion in the axial direction.

[0014] In the third aspect, the barrier is disposed opposite the fixed gear at the end of the carrier opposite the valve body in the axial direction. Therefore, for example, if the end of the carrier opposite the fixed gear in the axial direction is the upper end, the fixed gear can be prevented from shifting downward inside the motor-operated valve during use by contacting the barrier disposed at the upper end of the carrier from below. Furthermore, for example, if the barrier is disposed at the upper end of the carrier, the barrier is unlikely to interfere with the fixed gear even when the fixed gear and the carrier are stacked axially in this order during assembly of the motor-operated valve.

[0015] In a fourth aspect, in the motor-operated valve according to any one of the first to third aspects, each of a pair of adjacent pillars has an inner circumferential surface facing each other, and the inner circumferential surfaces facing each other form part of the same imaginary circle when viewed along the axial direction of the planetary gear reduction mechanism.

[0016] In the fourth aspect, each of a pair of adjacent support columns has inner circumferential surfaces that face each other, and the inner circumferential surfaces that face each other form part of the same imaginary circle when viewed along the axial direction of the planetary gear reduction mechanism. Therefore, the circle of the tooth tip of the planetary gear that is placed in the gap between the adjacent pair of support columns is concentric with the imaginary circle. In other words, the distance between the planetary gear and the inner circumferential surfaces of the pair of support columns that surround the planetary gear is aligned. Therefore, the planetary gear is less likely to slip out of the gap than when the distances between the planetary gear and the inner circumferential surfaces of the pair of support columns that surround the planetary gear are different.

[0017] In a fifth aspect, in the motor-operated valve according to any one of the first to fourth aspects, the input shaft, the output shaft and the fixed shaft of the planetary gear reduction mechanism are coaxial with a center axis.

[0018] In the fifth 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.

[0019] An actuator according to a sixth aspect of the present disclosure comprises a planetary gear reduction mechanism that reduces the rotation of a motor and outputs the reduced rotation, the carrier comprising a base and a plurality of support pillars standing on the base with gaps in a circumferential direction and supporting a plurality of planetary gears between the plurality of support pillars above the base, the carrier having a fence portion that is positioned radially outside one or more of the planetary gears of the carrier and overlaps with the gaps in the radial direction.

[0020] In the actuator according to the sixth aspect, as in the motor-operated valve according to the first aspect, the carrier is provided with a fence portion that is disposed radially outward of one or more planetary gears and overlaps with a gap between adjacent support posts. Therefore, when the planetary gears are disposed between the support posts inside the carrier and above the base during assembly, the fence portion can prevent the planetary gears from tipping outward from the carrier, regardless of whether or not there is an engagement structure between the planetary gears and the carrier. In other words, even if the carrier is miniaturized, the planetary gears can be stably disposed inside the carrier during assembly of the motor-operated valve.

[0021] According to the present disclosure, a technique that facilitates miniaturization of carriers can be provided.

[0022] 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 a cross-sectional view illustrating a carrier of the motor-operated valve according to the embodiment, cut along a plane perpendicular to the central axis, which is the rotation axis; FIG. 4 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. 5 is a cross-sectional view illustrating a motor-operated valve according to a comparative example, cut along a plane including the central axis, which is the rotation axis; FIG. 6 is an exploded perspective view illustrating a method of assembling the carrier of the motor-operated valve according to a first modified example; FIG. 7 is a perspective view illustrating a carrier of the motor-operated valve according to a second modified example; FIG. 8 is a perspective view illustrating a carrier of the motor-operated valve according to a third modified example; FIG. 9 is a cross-sectional view illustrating a carrier of the motor-operated valve according to the third modified example, cut along a plane perpendicular to the central axis, which is the rotation axis;

[0023] 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.

[0024] <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.

[0025] 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).

[0026] The screw mechanism converts the reduced rotation, i.e., output rotation, from the reduction mechanism 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 4.

[0027] (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 .

[0028] (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 a 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. 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.

[0029] (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.

[0030] 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.

[0031] (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.

[0032] (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.

[0033] 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.

[0034] 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.

[0035] (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.

[0036] 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. 4, 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.

[0037] (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. 4 ) 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. 4 ). The entire carrier 64 is supported so as to be able to rotate freely on the output gear 66.

[0038] 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.

[0039] 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.

[0040] (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.

[0041] (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.

[0042] (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.

[0043] 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.

[0044] 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.

[0045] (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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] (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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] (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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] (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.

[0061] 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).

[0062] 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.

[0063] 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.

[0064] (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. 4, a ring gear 62A1 is formed on the inner periphery of the main body 62A of the fixed gear 62.

[0065] A through-hole 62A2 is formed in the radial center of the ring-shaped main body 62A. As shown in Figure 4, 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 to the upper part of the gear case 61 are formed alternately in the circumferential direction.

[0066] 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.

[0067] (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.

[0068] (Output Gear) As shown in Fig. 4, the output gear 66 is a cylindrical member with a bottom, having 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) into which the cylindrical portion 70C of the output shaft 70 is press-fitted is formed at the radial center of the bottom 66A. 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 gear 65 of the carrier 64 located at the top stage in Fig. 4.

[0069] (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.

[0070] 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.

[0071] In this embodiment, no fitting structure is formed between the planet gear 65 and the carrier 64, but in the present disclosure, a fitting structure may be formed. The fitting structure may also function as a positioning portion between the planet gear 65 and the carrier 64. Regarding the fitting structure, for example, as shown in FIG. 5 , in the comparative example, a through hole 65P is formed in the center of the planet gear 65, into which a pin 64P of a fitting protrusion of the carrier 64 is rotatably fitted.

[0072] 5, a single washer-like plate 64C having a shaft hole 64C1 similar to the lower base 64A is placed on the upper surface of the carrier 64, with the planetary gears 65 fitted onto the pins 64P of the fitting protrusions. The pins 64P of the fitting protrusions and the fitting protrusions 64B1 at the tops of the support posts 64B are press-fitted into through holes 64C2 of the plate 64C, thereby rotatably fixing the planetary gears 65 to the carrier 64. An example of a fitting structure in this disclosure will be described later in a first modified example using FIG. 6.

[0073] (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. 3, 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] (Barrier Portion) Next, the barrier portion of the carrier 64 according to this embodiment will be described in detail with reference to FIGS. 2 and 3. As shown in FIG. 2, in this embodiment, the carrier 64 is provided with a barrier portion 64D. In this embodiment, the barrier portion 64D is disposed at the upper end of the carrier 64 in the axial direction in FIG. 2, i.e., at the end opposite the valve body in the axial direction, facing the fixed gear 62. In other words, as shown in FIG. 1, the fixed gear 62 can support the barrier portion 64D from below. In this disclosure, it is not essential that the barrier portion be disposed at the upper end of the carrier. In this embodiment, the axial direction is the direction in which the central axis X extends.

[0079] As shown in Fig. 2, the fence portion 64D in this embodiment is a plate-shaped member. In this embodiment, the main surface of the plate-shaped fence portion 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 fence portion when viewed from the front is not limited to this and may be any geometric shape, such as triangular or elliptical. In addition, the main surface of the fence portion may have a partial cutout or protrusion formed thereon.

[0080] 3, in this embodiment, the main surface of the plate-shaped fence portion 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 fence portion 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 fence portion in a plan view is not limited to this and can be any shape, such as a U-shape or a V-shape.

[0081] In this embodiment, the fence 64D is molded integrally with the base 64A and the support 64B by resin molding. In the present disclosure, the fence may be made of any material. Also, in the present disclosure, the fence and the support may be integrated, for example, by being manufactured separately from the support and then joined to the support.

[0082] In this embodiment, the fence portion 64D connects a pair of circumferentially adjacent support columns 64B. Note that in the present disclosure, it is not essential that the fence portion connects adjacent support columns. The fence portion may be provided on only one of the adjacent support columns, for example, like a cantilever beam.

[0083] In addition, although the present embodiment illustrates a case in which the upper and lower edges of the fence portion 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 fence portion 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 fence portion may extend circumferentially such that an imaginary extension line of the upper edge and an imaginary extension line of the lower edge in Fig. 2 intersect as they approach from one support post side to the other support post side.

[0084] The fence portions 64D function as outer covers for the planetary gears 65. In this embodiment, the fence portions 64D are arranged outside the three planetary gears 65 in the radial direction of the carrier 64 and facing the respective planetary gears 65.

[0085] In the present disclosure, the number of planetary gears 65 that the fence portion 64D is arranged to face may be one, or may be any number of two or more. That is, the fence portion 64D may be provided to face all of the plurality of planetary gears 65 that are 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 fence portion is arranged outside one or more planetary gears in the radial direction of the carrier and faces the planetary gear.

[0086] The fence portion 64D overlaps with the gap G between adjacent support posts 64B in the radial direction of the carrier 64. In the present embodiment, the fence portion 64D overlaps with one gap G in the radial direction of the carrier 64 over the entire circumferential direction of the one gap G, but the present disclosure is not limited to this. In the present disclosure, the fence portion may overlap with, for example, a portion of one gap G in the circumferential direction.

[0087] 3, in this embodiment, each of a pair of adjacent support columns 64B has inner circumferential surfaces IS1 and IS2 that face each other. Also, as shown in FIG. 3, the inner circumferential surfaces IS1 and IS2 that face each other form part of the same imaginary circle VC in a plan view taken along the axial direction of the reduction gear mechanism 60 (i.e., the direction in which the central axis X extends).

[0088] In this embodiment, the opposing inner circumferential surfaces IS1 and IS2 have the same curvature. In the present disclosure, it is not essential that the opposing inner circumferential surfaces of the pair of support columns form part of the same imaginary circle in a plan view. The opposing inner circumferential surfaces may form part of different imaginary circles in a plan view.

[0089] (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 4. First, the carrier 64 and the planetary gears 65 are integrated together. Specifically, 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.

[0090] In this embodiment, since no fitting structure is provided between the base 64A and the planetary gear 65, the lower end surface in the axial direction of the planetary gear 65, which contacts the upper surface of the base 64A, and the upper surface of the base 64A are not fixed by a fitting structure. However, as shown in Figure 3, in this embodiment, a fence portion 64D is provided at the position of the gap G between a pair of adjacent supports 64B.

[0091] Therefore, during assembly, even if no fitting structure is provided, the three planetary gears 65 are prevented from falling outward from the carrier 64 through the gap G between adjacent pairs of support columns 64B. Then, as shown in Fig. 2, a plate 64C is placed on top of the carrier 64 on the inside of which the three planetary gears 65 are arranged upright. The support columns 64B of the carrier 64 and the plate 64C are fitted together, and as a result, the carrier 64 and the planetary gears 65 are integrated as shown in Fig. 4.

[0092] 4, 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 located above the output gear 66. Next, the carrier 64 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 62A above the fixed gear 62.

[0093] 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.

[0094] Comparative Example Next, an electric valve 1Z according to a comparative example in which the fence portion 64D is not provided will be described with reference to Fig. 5. As shown in Fig. 5, the comparative example does not have the fence portion 64D, but has a pin 64P as a fitting protrusion extending upward from the top surface of the base 64A of the carrier 64, and a through hole 65P as a fitting hole corresponding to the fitting protrusion. For this reason, in the comparative example in which the fence portion 64D is not provided, it may be difficult to accurately form the fitting protrusion and the fitting hole when miniaturizing the carrier 64.

[0095] (Operation and Effect) In the motor-operated valve 1 according to this embodiment, the carrier 64 is provided with a fence portion 64D that is disposed outside one or more planetary gears 65 in the radial direction of the carrier 64 and overlaps with the gap G between adjacent support columns 64B. Therefore, during assembly, when the planetary gears 65 are disposed between the three support columns 64B above the base 64A inside the carrier 64, the fence portion 64D can prevent the planetary gears 65 from falling outward from the carrier 64, regardless of whether or not there is an interlocking structure between the planetary gears 65 and the carrier 64. In other words, even if the carrier 64 is miniaturized, the planetary gears 65 can be stably disposed inside the carrier 64 during assembly of the motor-operated valve 1.

[0096] Considering the difficulty of forming the fitting structure, it is possible to consider a means of simply not forming the fitting structure. However, if the fence portion 64D is not provided when assembling the motor-operated valve 1, even if the multiple planetary gears 65 are temporarily positioned on the base 64A inside the carrier 64, the planetary gears 65 will tend to fall to the outside of the carrier 64 at the position of the gap G until the sun gear engages with the multiple planetary gears 65. This reduces the ease of assembly of the motor-operated valve 1.

[0097] However, in this embodiment, the fence portion 64D prevents the planetary gear 65 from falling outward from the carrier 64 at the position of the gap G. Therefore, when miniaturizing the carrier 64, it is not necessary to precisely form the fitting protrusions and fitting holes that constitute the fitting structure. This facilitates miniaturization of the carrier 64 regardless of whether or not there is a fitting structure between the planetary gear 65 and the carrier 64. Similarly, in the actuator AC according to this embodiment, it is easy to facilitate miniaturization of the carrier 64 regardless of whether or not there is a fitting structure between the planetary gear 65 and the carrier 64.

[0098] In this embodiment, the carrier 64 is made of resin and is formed by resin molding. For example, if the diameter of the cylindrical carrier base is approximately 1 cm, the diameter of the multiple mating projections or mating holes provided in the base corresponding to the multiple planetary gears will be significantly smaller than the diameter of the base, at 1 mm or less. For this reason, it is technically very difficult to precisely mold the mating projections and mating holes made of resin. However, in this embodiment, there is no need to precisely mold the mating structures made of resin, which is particularly advantageous in terms of miniaturizing the carrier 64.

[0099] In this embodiment, the fence portions 64D connect a pair of adjacent support columns 64B in the circumferential direction, thereby improving the strength of the carrier 64.

[0100] Furthermore, in this embodiment, the fence portion 64D is disposed opposite the fixed gear 62 at the upper end of the carrier 64 in the axial direction, and therefore the fixed gear 62 comes into contact with the fence portion 64D disposed at the upper end of the carrier 64 from below, thereby preventing the carrier 64 from shifting downward inside the motor-operated valve 1 during use. Furthermore, when the fence portion 64D is disposed at the upper end of the carrier 64, the fence portion 64D is unlikely to interfere with the fixed gear 62, even when the fixed gear 62 and the carrier 64 are stacked in the axial direction in this order during assembly of the motor-operated valve 1.

[0101] In addition, in this embodiment, each of a pair of adjacent pillars 64B has inner surfaces IS1 and IS2 that face each other, and the inner surfaces IS1 and IS2 that face each other form part of the same imaginary circle VC when viewed in a plan view along the axial direction of the reduction mechanism 60.

[0102] Therefore, the circle of the tooth tip of the planetary gear 65 arranged in the gap G between a pair of adjacent support columns 64B and the imaginary circle VC are arranged concentrically. In other words, the distance between the planetary gear 65 and the inner circumferential surfaces IS1, IS2 of the pair of support columns 64B surrounding the planetary gear 65 is aligned. Therefore, the planetary gear 65 is less likely to come out of the gap G than when the distances between the planetary gear 65 and the inner circumferential surfaces IS1, IS2 of the pair of support columns 64B surrounding the planetary gear 65 are different.

[0103] In this embodiment, the input shaft, output shaft, and fixed shaft of the reduction mechanism 60 are coaxial with the central axis X. Therefore, a 3K type paradox planetary gear device can be realized.

[0104] (First Modification: Combination of Barrier Portion and Fitting Structure) Note that the present disclosure does not exclude the combination of a barrier portion and a fitting structure. In the present disclosure, a barrier portion can be provided on the carrier regardless of whether or not a fitting structure between the planet gear and the carrier is provided. For example, as shown in FIG. 6 , a fitting structure between the planet gear 65 and the carrier 64 may be formed while a barrier portion 64D is provided.

[0105] Specifically, a cylindrical lower protrusion 65L is provided at the lower end of a planetary gear 65 supported by a carrier 64V of the motor-operated valve according to the first modified example shown in Figure 6, and a cylindrical upper protrusion 65U is provided at the upper end of the planetary gear 65. The lower protrusion 65L and the upper protrusion 65U are fitting protrusions that form a fitting structure.

[0106] Furthermore, a through hole 62A2 is provided in the base 64A of the carrier 64V in correspondence with the lower protrusion 65L. The through hole 62A2 is a fitting hole portion that forms a fitting structure together with the lower protrusion 65L. In other words, the through hole 62A2 is a boss hole for guiding the lower protrusion 65L.

[0107] In the first modified example, the mating holes that form the mating structure together with the upper protrusions 65U of the planetary gears 65 are not provided in the plate 64C of the carrier 64. In the present disclosure, mating holes that form the mating structure together with the upper protrusions of the planetary gears may be provided. The configurations of the other members of the carrier 64V of the motor-operated valve according to the first modified example, excluding the lower protrusions 65L, the upper protrusions 65U, and the through holes 62A2, are the same as the members of the same names in the motor-operated valve 1 according to the present embodiment, and therefore will not be described again.

[0108] (Operational Effects of the First Modification) In the motor-operated valve according to the first modification, as in the present embodiment, the planetary gear 65 can be stably positioned inside the carrier 64V during assembly of the motor-operated valve, which facilitates miniaturization of the carrier 64V. Furthermore, in the first modification, the engagement structure between the planetary gear 65 and the carrier 64V is provided, which further enables the planetary gear 65 to be stably supported by the carrier 64V during assembly. Other operational effects of the first modification are the same as those of the present embodiment.

[0109] (Second Modification: Position of Fence Section) In the present embodiment, the fence section 64D is disposed at the upper end of the carrier 64, but the present disclosure is not limited to this. For example, as shown in FIG. 7 , the fence section 64D may be disposed at the center of the carrier 64W in the up-down direction.

[0110] In the carrier 64W of the motor-operated valve according to the second modification shown in Fig. 7, the barrier 64D is located at the middle position in the vertical direction, but this is not limited to this in the present disclosure. For example, the barrier may be located closer to the upper end or the lower end in the vertical direction in Fig. 7. The location of the barrier can be changed as desired.

[0111] In the second modified example, the barrier portion 64D may be formed so that the lower portion of the internal space of the fixed gear 62 has a larger diameter in the radial direction than the upper portion, and may be disposed at the lower portion of the expanded internal space so as to face the inner circumferential surface of the fixed gear 62. Alternatively, the barrier portion 64D may be disposed so as to face the inner circumferential surface of the gear case. The configuration of the carrier 64W of the motor-operated valve according to the second modified example, other than the position of the barrier portion 64D, is the same as the configuration of the motor-operated valve 1 according to the present embodiment, and therefore a repeated description will be omitted.

[0112] (Effects of the Second Modification) In the motor-operated valve according to the second modification, as in the present embodiment, the planetary gear 65 can be stably positioned inside the carrier 64W during assembly of the motor-operated valve, which facilitates miniaturization of the carrier 64W. Furthermore, in the second modification, the position of the fence portion 64D is not limited to the upper end of the carrier 64W, which allows for a wider range of carrier design options. Other effects of the second modification are similar to those of the present embodiment.

[0113] (Third Modification: Slits in the Barrier Portion) In the present embodiment, the case where the barrier portion 64D connects a pair of adjacent support columns 64B has been illustrated, but the present disclosure is not limited to this. Specifically, the barrier portion 64D of the carrier 64X of the motor-operated valve according to the third modification illustrated in Figures 8 and 9 has a first portion 64D1 provided on one of the pair of adjacent support columns 64B and a second portion 64D2 provided on the other of the pair of adjacent support columns 64B.

[0114] The first portion 64D1 and the second portion 64D2 are aligned along the circumferential direction of the carrier 64X, with a slit 64S sandwiched therebetween. In other words, the slit 64S is a gap extending in the vertical direction in Figure 8. The configuration of the carrier 64X of the motor-operated valve according to the third modification, other than the fence portion 64D, 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.

[0115] (Effects of the Third Modification) In the motor-operated valve according to the third modification, as in the present embodiment, the planetary gear 65 can be stably positioned inside the carrier 64V during assembly of the motor-operated valve, which facilitates miniaturization of the carrier 64V. Furthermore, in the third modification, a slit 64S extending in the vertical direction is formed in the fence portion 64D of the carrier 64X. The component volume of the carrier 64X is reduced by the amount of the slit 64S, which reduces the manufacturing cost of the carrier 64V. Other effects of the third modification are the same as those of the present embodiment.

[0116] 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.

[0117] The disclosure of Japanese Patent Application No. 2023-223590, 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 that includes a carrier having a base and a plurality of support columns erected on the base with gaps in the circumferential direction and supporting a plurality of planetary gears between the plurality of support columns above the base, the carrier having a fence portion that is disposed outside one or more of the planetary gears whose shafts are not supported at their upper ends in the radial direction of the carrier and that overlaps with the gaps in the radial direction, and that reduces the rotation of the motor before outputting it; a valve body that controls the opening degree of the valve by rotating the output; An electrically operated valve comprising:

2. The fence portion connects a pair of the posts adjacent to each other in the circumferential direction. The motor-operated valve according to claim 1 .

3. the planetary gear type reduction mechanism has a fixed gear, The fence portion is disposed at an end portion of the carrier opposite to the valve main body portion in the axial direction, facing the fixed gear. The motor-operated valve according to claim 1 or 2.

4. Each of the adjacent pair of support columns has an inner circumferential surface facing each other, the inner circumferential surfaces facing each other form parts of the same imaginary circle when viewed along the axial direction of the planetary gear type reduction mechanism.

3. The motor-operated valve according to claim 1 or 2.

5. The input shaft, output shaft and fixed shaft of the planetary gear type reduction mechanism are coaxial with the central axis.

3. The motor-operated valve according to claim 1 or 2.

6. a planetary gear type reduction mechanism that includes a carrier having a base and a plurality of support columns erected on the base with gaps in the circumferential direction and supporting a plurality of planetary gears between the plurality of support columns above the base, the carrier having a fence portion that is arranged outside one or more of the planetary gears whose shafts are not supported at their upper ends in the radial direction of the carrier and that overlaps with the gaps in the radial direction, and that reduces the rotation of a motor before outputting it; An actuator comprising: