Electric valve and actuator

Abstract

An electric valve comprising: a planetary gear speed reduction mechanism that reduces and outputs the rotation of a motor, said mechanism having a carrier that supports a plurality of planet gears; a valve body that controls the degree of opening of a valve by means of the output rotation; and a fixed gear that is provided to the planetary gear speed reduction mechanism, said fixed gear comprising a body that has a ring gear which meshes with the planet gears formed on the inner peripheral side thereof, and a restraining part that is provided on the opposite side of the body from the valve body in the axial direction and protrudes from the ring gear to a position overlapping the planet gears when viewed in the axial 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 (i.e., planetary gears). In JP 2021-131160 A, the carrier has a base on which one axial end of the planetary gears is disposed, multiple support columns extending from the base toward the opposite side from the valve body, and a plate disposed opposite the other axial end of the planetary gears.

[0004] A protrusion is formed at the tip of each of the plurality of support posts, and through holes into which the respective protrusions fit are formed in the plate at positions corresponding to the respective protrusions of the plurality of support posts.

[0005] In assembling the motor-operated valve, the planetary gears are disposed between the base and the plate inside the carrier. When the motor-operated valve is in use, the plate prevents the planetary gears from passing through the through-holes of the ring-shaped fixed gear to the sun gear member located on the opposite side of the valve body in the axial direction.

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

[0007] In JP 2021-131160 A, during assembly of the motor-operated valve, when assembling the carrier, when attaching the plate to the support, it is necessary to align the position of the protrusion on the support with the position of the through-hole in the plate while maintaining the state in which multiple planetary gears are arranged between the multiple support posts. It may also be necessary to fix the aligned support and plate by ultrasonic welding or the like. In other words, during assembly of the motor-operated valve, the burden of work required to integrate the support and plate is incurred.

[0008] In view of the above, the present disclosure provides a technique that can reduce the burden of assembly work compared to when a plate is provided on a carrier.

[0009] The electric valve according to the first aspect of the present disclosure comprises a planetary gear reduction mechanism having a carrier supporting a plurality of planetary gears and which reduces the rotation of a motor and outputs the reduced rotation; a valve main body which controls the opening degree of the valve by the rotation of the output; and a fixed gear provided in the planetary gear reduction mechanism, the main body having a ring gear formed on its inner circumference which meshes with the planetary gears, and a retaining portion provided on the axial side of the main body from the valve main body and protruding from the ring gear to a position overlapping with the planetary gears when viewed along the axial direction.

[0010] In the motor-operated valve according to the first aspect, the fixed gear is provided on the opposite side of the main body from the valve main body in the axial direction and has a retaining portion that protrudes from the ring gear to a position that overlaps with the planetary gears as viewed along the axial direction. Therefore, even if a plate is not provided on the carrier, the retaining portion can prevent the planetary gears from passing through the through-holes in the ring-shaped main body of the fixed gear to the opposite side of the valve main body in the axial direction. As a result, there is no burden of work involved in integrating the support and the plate.

[0011] In a second aspect, in the motor-operated valve according to the first aspect, the main body portion and the pressing portion are integrally molded as a single member.

[0012] In the second aspect, the main body and the restricting portion are integrally molded as a single member, which reduces the number of components that make up the motor-operated valve compared to when the main body and the restricting portion are separate members.

[0013] In a third aspect, in the electric valve according to the first or second aspect, the planetary gear has a shaft portion extending along the axial direction and teeth provided radially outside the shaft portion, and the retaining portion overlaps with the shaft portion of the planetary gear when viewed along the axial direction.

[0014] In the third aspect, the retaining portion overlaps with the shaft portion of the planetary gear when viewed in the axial direction. That is, the retaining portion protrudes from the ring gear to a position where it overlaps with the shaft portion radially inward of the teeth. Therefore, compared to, for example, a case where the retaining portion protrudes to a position where it overlaps only with the teeth in the radial direction, it is possible to further prevent the planetary gear from coming off.

[0015] In a fourth aspect, in an electric valve according to any one of the first to third aspects, the carrier comprises a base and a plurality of pillars erected on the base with gaps therebetween in a circumferential direction, the plurality of planetary gears are supported between the plurality of pillars, and a fence portion overlapping the gaps in the radial direction of the carrier is positioned outside one or more of the planetary gears.

[0016] In the fourth aspect, a barrier portion that overlaps with the gap in the radial direction of the carrier is disposed outside one or more of the planetary gears. Therefore, when the planetary gears are disposed between the plurality of support columns above the base inside the carrier, the barrier portion can prevent the planetary gears from falling outside 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.

[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 is a planetary gear type reduction mechanism having a carrier that supports a plurality of planetary gears and that decelerates and outputs the rotation of a motor, the planetary gear type reduction mechanism comprising: a main body portion having a ring gear formed on its inner periphery that meshes with the planetary gears; and a retaining portion that is provided on the opposite side of the main body portion in the axial direction from a valve main body portion that controls the opening degree of the valve by rotation of the output, and that protrudes from the ring gear to a position that overlaps with the planetary gears when viewed along the axial direction.

[0020] In the actuator according to the sixth aspect, as in the motor-operated valve according to the first aspect, the fixed gear is provided on the opposite side of the main body in the axial direction from the valve main body that controls the valve opening by rotation of the output, and has a retaining portion that protrudes from the ring gear to a position that overlaps with the planetary gears as viewed along the axial direction. Therefore, even if a plate is not provided on the carrier, the retaining portion can prevent the planetary gears from passing through the through-holes in the ring-shaped main body of the fixed gear to the opposite side of the valve main body in the axial direction. As a result, there is no burden of work involved in integrating the support column and the plate.

[0021] According to the present disclosure, a technique can be provided that can reduce the burden of assembly work compared to when a plate is provided on a carrier.

[0022] FIG. 1 is a cross-sectional view illustrating a motor-operated valve according to an embodiment of the present disclosure, cut by a plane including the central axis, which is the rotation axis; FIG. 2 is a perspective view illustrating a fixed gear of the motor-operated valve according to the embodiment, as viewed from above; FIG. 3 is a perspective view illustrating a fixed gear of the motor-operated valve according to the embodiment, as viewed from below; FIG. 4 is a perspective view illustrating a carrier and planetary gear of the motor-operated valve according to the embodiment; FIG. 5 is a cross-sectional view illustrating a carrier and planetary gear of the motor-operated valve according to the embodiment, cut by a plane perpendicular to the central axis, which is the rotation axis; FIG. 6 is an exploded perspective view illustrating a method of assembling the fixed gear, carrier, and output gear of the motor-operated valve according to the embodiment.

[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 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 and 2.

[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 located at the radial center. A boss (not shown) extending vertically downward in FIG. 1 is provided at the radial center 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 the reduction mechanism 60, is formed radially outward from the boss.

[0034] (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.

[0035] 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.

[0036] (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. 2) 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.

[0037] 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.

[0038] 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.

[0039] (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.

[0040] (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.

[0041] (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.

[0042] 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.

[0043] 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.

[0044] (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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] (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 each of the first opening 10A and the second opening 10B.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] (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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] (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.

[0060] 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).

[0061] 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.

[0062] 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.

[0063] (Fixed Gear) Next, the fixed gear 62 according to this embodiment will be described in detail with reference to FIGS. 2 and 3. The fixed gear 62 is provided in the reduction mechanism 60. The fixed gear 62 is produced, for example, by molding a resin. As shown in FIG. 2, the fixed gear 62 has a main body portion 62A and a retaining portion 62C. The main body portion 62A is ring-shaped. A ring gear 62A1 that meshes with the planetary gear 65 is formed on the inner periphery of the main body portion 62A.

[0064] 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 main body 62A 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.

[0065] 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.

[0066] 2, the retaining portion 62C in this embodiment is ring-shaped. Note that, in the present disclosure, the shape of the retaining portion is not limited to this. For example, the retaining portion may protrude from a portion of the ring gear 62A1 toward the central axis X. However, by having the retaining portion 62C in a ring shape that protrudes from the entire ring gear 62A1 toward the central axis X, as in this embodiment, it is possible to more reliably prevent the carrier 64 from coming off.

[0067] The retaining portion 62C is provided on the axial side of the main body 62A opposite to the valve main body (upper side in FIG. 2). As shown in FIG. 3, the retaining portion 62C protrudes from the ring gear 62A1 to a position overlapping with the planetary gear 65 when viewed in the axial direction (i.e., the direction in which the central axis X extends). FIG. 3 illustrates a state in which the retaining portion 62C protrudes to a position overlapping with the upper protrusion 65U of the planetary gear 65 when viewed in the direction in which the central axis X extends.

[0068] In this embodiment, the main body portion 62A and the pressing portion 62C are integrally molded as a single member, for example, by resin molding. This disclosure is not limited to this, and the main body portion and the pressing portion may be manufactured separately and then integrated by fitting, welding, etc. Also, in this disclosure, the main body portion and the pressing portion may be integrally molded as a single fixed gear member, for example, by cutting out from a single block of resin material.

[0069] 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.

[0070] (Output Gear) As shown in Fig. 6, 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, which is located in the vertical center in Fig. 6.

[0071] (Planetary Gear) As shown in Fig. 4, the planetary gear 65 is a cylindrical member. As shown in Figs. 4 and 5, the planetary gear 65 has a shaft portion 65A extending along the axial direction and teeth 65B. The teeth 65B are provided as a gear portion on the radially outer side of the shaft portion 65A, i.e., on the outer periphery of the planetary gear 65. 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.

[0072] 4, a cylindrical lower protrusion 65L is provided at the lower end of the planetary gear 65, and a cylindrical upper protrusion 65U is provided at the upper end of the planetary gear 65. During assembly, the three planetary gears 65 are arranged inside the carrier 64 with the lower protrusions 65L on one end face side (i.e., the lower end face side in FIG. 4) of each of the three planetary gears 65 facing the top of the base 64A of the carrier 64.

[0073] 4 and 5, the lower protrusion 65L and the upper protrusion 65U are located inside the shaft portion 65A in a plan view along the axial direction. Therefore, as can be seen from the state in which the retaining portion 62C of the fixed gear 62 overlaps the upper protrusion 65U in FIG. 2, in this embodiment, the retaining portion 62C overlaps with the shaft portion 65A of the planetary gear 65 in a plan view along the axial direction. Note that in the present disclosure, it is not essential that the retaining portion 62C overlap with the shaft portion 65A of the planetary gear 65 in a plan view along the axial direction. For example, it is not excluded that the retaining portion 62C overlaps only with the tooth 65B in the radial direction.

[0074] In this embodiment, the upper and lower structures of the planetary gear 65 in FIG. 4 are the same. That is, the planetary gear 65 of this embodiment functions as a planetary gear even when it is upside down in FIG. 4 . In other words, the planetary gear 65 can be used without being limited to the up-down direction of the planetary gear 65 in FIG. 4 . Therefore, when assembling the motor-operated valve 1, it is not necessary to consider the up-down direction of the planetary gear 65, which makes assembly easy. Note that in the present disclosure, the upper and lower structures of the planetary gear 65 in FIG. 4 may be different from each other.

[0075] In the present disclosure, a fitting structure may be formed between the planetary gear 65 and the carrier 64. The fitting structure may also function as a positioning portion between the planetary gear 65 and the carrier 64. With regard to the fitting structure, for example, a pin extending upward from the upper surface of the base 64A of the carrier 64 in FIG. 4 may be provided as a fitting protrusion. Furthermore, a through-hole may be formed in the center of the planetary gear 65 as a fitting hole portion corresponding to the pin of the fitting protrusion of the carrier 64, into which the pin is rotatably fitted.

[0076] Furthermore, in the present disclosure, the lower protrusion 65L and the upper protrusion 65U may be used as mating protrusions that form a mating structure. That is, a mating hole corresponding to the lower protrusion 65L may be formed in the base 64A. Also, a mating hole corresponding to the upper protrusion 65U may be formed in the retaining portion 62C of the fixed gear 62. Furthermore, it is not necessary to form a mating hole in both the base 64A and the retaining portion 62C, and it may be formed in only one of them.

[0077] (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. 5, the carrier 64 has a base 64A having an axial hole 64A1 through which the shaft 42 passes at its radial center. The base 64A is a disk-shaped member. As shown in FIG. 4, the base 64A is the bottom of the carrier 64.

[0078] As shown in Fig. 4, 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.

[0079] Three planetary gears 65 are arranged upright in three gaps G formed between adjacent pairs of the three support columns 64B. Each of the three planetary gears 65 is rotatable while sandwiched between the lower base 64A in FIG. 1 and the retaining portion 62C of the upper fixed gear 62. The three planetary gears 65 are rotatably supported by the carrier 64 between the three support columns 64B above the base 64A in FIG. 2.

[0080] (Barrier) As shown in FIG. 4 , in this embodiment, the carrier 64 is provided with a bar 64D. In this embodiment, the bar 64D is disposed at the axial center of the carrier 64, i.e., between the fixed gear 62 and the output gear 66 in the axial direction, facing the gear case 61. In other words, as shown in FIG. 1 , the output gear 66 can support the bar 64D from below. In this disclosure, it is not essential that the bar be disposed at the axial center of the carrier. In this embodiment, the axial direction is the direction in which the central axis X extends. In this disclosure, the bar may be disposed at the end of the carrier on the valve body side in the axial direction, or at the end opposite the valve body in the axial direction. The bar may be disposed at any position between both ends in the axial direction.

[0081] As shown in Fig. 4, 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.

[0082] 5, 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.

[0083] 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.

[0084] 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.

[0085] In addition, although the present embodiment illustrates a case in which the upper and lower edges of the fence portion 64D in Fig. 4 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. 4 or from the bottom to the top in Fig. 4. 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. 4 intersect as they approach from one support post side to the other support post side.

[0086] 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.

[0087] 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.

[0088] 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.

[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, 3, 4, and 6. First, the carrier 64 and the planetary gears 65 are integrated together. Specifically, as shown in Figure 4, the three planetary gears 65 are arranged upright in three gaps G formed between pairs of adjacent support columns 64B on the upper surface of the base 64A of the carrier 64.

[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 5, 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 a pair of adjacent supports 64B. As shown in Fig. 6 , the output gear 66 and the carrier 64 are integrated by inserting the carrier 64, on which the three planetary gears 65 are arranged inside, from above into the output gear 66 arranged on the lower side in the vertical direction. Note that the carrier 64 alone may first be inserted into the output gear 66, and then the three planetary gears 65 may be arranged inside the carrier 64.

[0092] Next, the fixed gear 62 with the gear case 61 attached is inserted from above into the carrier 64 integrated with the output gear 66. As a result, the fixed gear 62 is disposed above the output gear 66.

[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] (Effects) In the motor-operated valve 1 according to this embodiment, the fixed gear 62 is provided on the axially opposite side of the main body 62A from the valve main body VB, and has a ring-shaped retaining portion 62C that protrudes from the ring gear 62A1 to a position that overlaps with the planetary gears 65 as viewed along the axial direction. Therefore, even if a plate is not provided on the carrier, the retaining portion 62C can prevent the planetary gears 65 from passing through the through-holes in the ring-shaped main body 62A of the fixed gear 62 and slipping out to the axially opposite side from the valve main body VB. As a result, no additional work is required to integrate the support column 64B and the plate. Therefore, the assembly work can be made easier than when a plate is provided on the carrier 64.

[0095] Similarly, in the actuator AC according to this embodiment, the retaining portion 62C can prevent the planetary gear 65 from passing through the through-hole of the ring-shaped main body portion 62A of the fixed gear 62 and slipping out to the opposite side of the valve main body portion VB in the axial direction. Therefore, no work load is required to integrate the support column 64B and the plate, and the burden of the assembly work can be reduced compared to when a plate is provided on the carrier 64.

[0096] In this embodiment, the main body 62A and the restricting portion 62C are integrally molded as a single member, which reduces the number of components that make up the motor-operated valve compared to when the main body 62A and the restricting portion 62C are separate members.

[0097] In addition, in this embodiment, the retaining portion 62C overlaps with the shaft portion 65A of the planetary gear 65 in a plan view seen along the axial direction. That is, the retaining portion 62C protrudes from the ring gear 62A1 to a position where it overlaps with the shaft portion 65A radially inward of the teeth 65B. Therefore, the planetary gear 65 can be more effectively prevented from coming loose than, for example, when the retaining portion 62C protrudes to a position where it overlaps only with the teeth 65B in the radial direction.

[0098] Furthermore, in this embodiment, the fence portions 64D that overlap the gaps G in the radial direction of the carrier 64 are arranged outside one or more planetary gears 65. Therefore, when the planetary gears 65 are arranged between the three support columns 64B above the base 64A inside the carrier 64 during assembly, the fence portions 64D can prevent the planetary gears 65 from falling outside 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 made smaller, the planetary gears 65 can be stably arranged inside the carrier 64 during assembly of the motor-operated valve 1.

[0099] Considering the difficulty of molding the fitting structure due to miniaturization, it is possible to consider 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.

[0100] 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 reducing the size of the carrier 64, it is not necessary to precisely form the fitting protrusions and fitting holes that constitute the fitting structure. Therefore, it is easy to promote the miniaturization of the carrier 64 regardless of whether or not there is a fitting structure between the planetary gear 65 and the carrier 64.

[0101] 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 65 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 structure made of resin, which is particularly advantageous in terms of miniaturizing the carrier 64.

[0102] 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.

[0103] Although the present disclosure has been described by the above disclosed embodiments, the descriptions and drawings forming part of this disclosure should not be understood to limit the present disclosure. 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.

[0104] The disclosure of Japanese Patent Application No. 2023-223591, 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 motorized valve comprising: a planetary gear type reduction mechanism having a carrier that supports a plurality of planetary gears and that reduces and outputs the rotation of a motor; a valve body portion that controls the opening degree of a valve by the rotation of the output; and a fixed gear provided in the planetary gear type reduction mechanism, the fixed gear having a main body portion in which a ring gear that meshes with the planetary gears is formed on the inner peripheral side, and a restraining portion provided on the side opposite to the valve body portion in the axial direction of the main body portion and protruding from the ring gear to a position overlapping the planetary gears when viewed along the axial direction.

2. The motorized valve according to claim 1, wherein the main body portion and the restraining portion are integrally formed as one member.

3. The motorized valve according to claim 1 or 2, wherein the planetary gear has a shaft portion that extends along the axial direction and a gear portion provided outside the shaft portion in the radial direction, and the restraining portion overlaps the shaft portion of the planetary gear when viewed along the axial direction.

4. The motorized valve according to any one of claims 1 or 2, wherein the carrier includes a base and a plurality of struts erected on the base with a gap in the circumferential direction, the plurality of planetary gears are supported between the plurality of struts, and a fence portion overlapping the gap in the radial direction of the carrier is disposed outside one or more of the planetary gears.

5. The motorized valve according to claim 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.

6. An actuator comprising: a planetary gear type reduction mechanism having a carrier that supports a plurality of planetary gears and that reduces and outputs the rotation of a motor, the planetary gear type reduction mechanism being provided with a fixed gear having a main body portion in which a ring gear that meshes with the planetary gears is formed on the inner peripheral side, and a restraining portion provided on the side opposite to a valve body portion that controls the opening degree of a valve by the rotation of the output in the axial direction of the main body portion and protruding from the ring gear to a position overlapping the planetary gears when viewed along the axial direction.

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