Electric valve and planetary gear type speed reducing mechanism

Abstract

The utility model provides a novel technology capable of improving the degree of freedom of design in an electric valve and a planetary gear type speed reduction mechanism. The electric valve includes: an electric motor; a planetary gear-type speed reduction mechanism (speed reduction mechanism (60)) having a planetary gear (65) provided with a first tooth (T1) rotated by an input of an electric motor, and a second tooth (T2) provided corresponding to the first tooth (T1) and having a modulus different from that of the first tooth (T1), and an output gear (66) meshing with the second tooth (T2). An output rotation in which the input rotation is decelerated; and a valve main body part for controlling the opening degree of the valve through output rotation.

Description

Technical Field

[0001] The utility model relates to an electric valve and a planetary gear type speed reduction mechanism. Background Art

[0002] Conventionally, as disclosed in Patent Document 1, as an electric valve that opens and closes a valve via an electric motor, there is known an electric valve of a type that decelerates the input rotation of a rotor through a planetary gear type reduction mechanism and transmits the decelerated output rotation to a screw mechanism portion that controls the opening and closing of the valve. Specifically, Patent Document 1 discloses a differential gear mechanism of a singular planetary gear type. In the differential gear mechanism, it is possible to rotate at a relatively high reduction ratio relative to the fixed gear according to the difference in the number of teeth between the fixed gear and the output gear.

[0003] In addition, as another example of a planetary gear type reduction mechanism, Patent Document 2 discloses a 3K type planetary gear device, which is not an electric valve but in which three basic shafts consisting of an input shaft, an output shaft, and a fixed shaft all have the same rotation axis as the central axis of the device.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 4936941

[0007] Patent Document 2: Japanese Patent No. 6782494

[0008] Technical problems to be solved by the utility model

[0009] Here, in one planetary gear, the teeth of the portion meshing with the fixed gear are referred to as "first teeth", and the teeth of the portion meshing with the output gear at a position different from the first teeth are referred to as "second teeth". In the case of Patent Documents 1 and 2, in one planetary gear, the module of the first teeth is the same as the module of the second teeth.

[0010] Therefore, the design of not only the planetary gears but also the design of other gear elements such as the sun gear meshing with the planetary gears, the fixed gear and the output gear is restricted by the condition that the module of the first teeth in the planetary gears is consistent with the module of the second teeth. As a result, there is a problem that the degree of freedom in the design of the planetary gear type reduction mechanism and the degree of freedom in the design of the electric valve using the planetary gear type reduction mechanism are reduced as a whole. Utility Model Content

[0011] In view of the above, the utility model provides a new technology capable of improving the degree of freedom of design in an electric valve and a planetary gear type reduction mechanism.

[0012] Technical means for solving technical problems

[0013] The electric valve involved in the first method comprises: an electric motor; a planetary gear reduction mechanism, the planetary gear reduction mechanism having a planetary gear and an output gear, the planetary gear having a first tooth and a second tooth, the first tooth being input with the input rotation of the electric motor, the second tooth being arranged corresponding to the first tooth and having a module different from the module of the first tooth, the output gear being meshed with the second tooth to output an output rotation in which the input rotation is reduced; and a valve body, the valve body controlling the opening of the valve through the output rotation.

[0014] In the electric valve according to the first aspect, the planetary gear speed reduction mechanism can be designed without being restricted by the condition that the modules of the first teeth and the modules of the second teeth match each other, so the degree of freedom in designing the electric valve can be increased.

[0015] The second method is that, in the electric valve involved in the first method, the planetary gear reduction mechanism comprises: a fixed gear, which is arranged in the input area and has a number of teeth different from the number of teeth of the output gear; and a sun gear, which is concentrically arranged with the fixed gear and is input to the input rotation, and the sun gear is meshed with the first tooth of the planetary gear.

[0016] In the second aspect, in particular, a planetary gear type reduction mechanism including a fixed gear and a sun gear can be realized.

[0017] According to a third aspect, in the electric valve according to the second aspect, a diameter of a tooth bottom circle of the fixed gear is 15 mm or less.

[0018] In the third aspect, it is possible to improve the degree of freedom in designing a small electric valve in which the diameter of the tooth bottom circle of the fixed gear is 15 mm or less.

[0019] The fourth aspect is that, in the electric valve involved in any one of the first aspect to the third aspect, it comprises: a valve body, which has a valve chamber formed inside; a valve seat, which is formed on a part of the wall surface of the valve chamber and has an opening; a valve core, which is configured to be able to open and close the opening of the valve seat; a valve stem, which makes the valve core contact and separate from the valve seat; a cylindrical shell, which is installed on the valve body and forms a space between the shell and the valve body; an excitation device of the motor, which is installed on the outer periphery of the shell; a permanent magnet type rotor assembly, which is rotatably supported inside the shell and driven to rotate by the excitation device; and a threaded mechanism part, which converts the output rotation from the planetary gear reduction mechanism into a contact and separation action of the valve core relative to the valve seat and transmits it to the valve stem, and the rotor assembly and the planetary gear reduction mechanism are arranged in the space between the valve body and the shell.

[0020] In the fourth aspect, also in the electric valve, in particular, the degree of freedom in designing the electric valve in which the rotor assembly and the planetary gear type speed reduction mechanism are arranged in the space between the valve body and the housing can be improved.

[0021] A fifth aspect is the electric valve according to any one of the first to fourth aspects, wherein the output gear is a bottomed tubular member having a bottom and a wall rising from a peripheral edge of the bottom, and a storage space capable of accumulating a fluid is formed inside the tubular member.

[0022] Here, for example, by making the number of teeth of the second teeth of the planetary gear the same as the number of teeth of the first teeth, and making the diameter of the pitch circle of the second teeth smaller than the diameter of the pitch circle of the first teeth, so that the module of the second teeth is smaller than the module of the first teeth, the number of teeth of the output gear meshing with the second teeth can be reduced. Therefore, compared with the case where the number of teeth of the output gear is the same, the groove width between adjacent teeth in the output gear, in other words, the gap is enlarged. In the fifth embodiment, the gap is enlarged, and the volume of the fluid that can be accumulated in the storage space can be increased by a corresponding amount. For example, in the case where the accumulated fluid is a lubricating fluid, the volume of the lubricating fluid that can be maintained in the storage space is increased, so the lubricity of the electric valve can be improved.

[0023] The planetary gear reduction mechanism involved in the sixth embodiment has a planetary gear and an output gear, the planetary gear has a first tooth and a second tooth, the first tooth is input with an input rotation from the outside, the second tooth is arranged corresponding to the first tooth and has a module different from the module of the first tooth, and the output gear meshes with the second tooth to output an output rotation that is a reduction of the input rotation.

[0024] In the planetary gear type reduction mechanism involved in the sixth aspect, similarly to the case of the electric valve involved in the first aspect, since it is not restricted by the condition of making the module of the first teeth and the module of the second teeth consistent, the degree of freedom in designing the planetary gear type reduction mechanism can be increased.

[0025] Effect of utility model

[0026] According to the electric valve of the present invention, a new technology capable of improving the degree of freedom in designing the electric valve and the planetary gear type speed reduction mechanism can be provided, and an assembly method of the electric valve using the technology can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a cross-sectional view illustrating the electric valve according to the embodiment of the present invention cut along a plane including the central axis as a rotation axis.

[0028] Figure 2 This is a perspective view illustrating a partially cutaway portion of the interior of a singular planetary gear type speed reduction mechanism in the electric valve according to the present embodiment.

[0029] Figure 3 It is a top view for explaining the input region of the singular planetary gear type reduction mechanism according to the present embodiment.

[0030] Figure 4 It is a plan view for explaining the output region of the singular planetary gear type speed reduction mechanism according to the present embodiment.

[0031] Figure 5 It is a perspective view for explaining the planetary gear of the singular planetary gear type reduction mechanism according to the present embodiment.

[0032] Figure 6 It is a front view for explaining the planetary gear of the singular planetary gear type reduction mechanism involved in this embodiment.

[0033] Figure 7 This is a bottom view of the planetary gear of the singular planetary gear type speed reduction mechanism according to the present embodiment, viewed from the side of the second tooth.

[0034] Explanation of symbols

[0035] 1 Electric valve

[0036] 2 Motor excitation device (motor)

[0037] 3 Coils

[0038] 4 Circuit

[0039] 5 Mounting parts

[0040] 10 Valve body

[0041] 12 Valve chamber

[0042] 14 throttle holes

[0043] 17 Valve seat

[0044] 18A, 18B piping

[0045] 20 Bearing parts

[0046] 24 Compression coil spring

[0047] 26 Spring bearing parts

[0048] Trail 26A

[0049] 26B large diameter part

[0050] 26C flange

[0051] 26D step part

[0052] 30 Shell

[0053] 40 bearings

[0054] 41 holes

[0055] 42 Axis

[0056] 50 rotor assembly

[0057] 54 sun gear parts

[0058] 56 Sun gear

[0059] 58 through holes

[0060] 60 planetary gear reduction mechanism

[0061] 61 Gear Box

[0062] 62 Fixed Gear

[0063] 62A ring gear

[0064] 64 planetary gear carrier

[0065] 65 planetary gear

[0066] 65H hole

[0067] 66 Output gear

[0068] 66A bottom

[0069] 66B wall

[0070] 66C hole

[0071] 66D Output side internal gear

[0072] 70 Output shaft

[0073] 70A first hole

[0074] 70B second hole

[0075] 70C cylindrical part

[0076] 71 threaded shaft

[0077] 71A protrusion

[0078] 71B concave part

[0079] 72 cage

[0080] 73 bearings

[0081] 74 goals

[0082] 74A ball bearing parts

[0083] 75 valve stem

[0084] 75A spring bearing

[0085] 76 valve core

[0086] A1 First Center Line

[0087] A2 Second Center Line

[0088] C1 first pitch circle

[0089] C2 second pitch circle

[0090] Pitch circle of the internal gear on the CT output side

[0091] G1 first groove width

[0092] G2 second groove width

[0093] Groove width of GT output side internal gear

[0094] H1 first tooth height

[0095] H2 Second tooth height

[0096] R1 input area

[0097] R2 output area

[0098] Storage Space

[0099] T1 first tooth

[0100] T2 second tooth

[0101] V Center axis of planetary gear

[0102] X center axis. DETAILED DESCRIPTION

[0103] The present embodiment is described below. In the following description of the drawings, the same or similar parts are marked with the same or similar symbols. However, the drawings are schematic, and the relationship between thickness and plane size, the ratio of the thickness of each device or component, etc. are sometimes different from reality. Therefore, the specific thickness and size should be determined with reference to the following description. In addition, there are also cases where the drawings contain parts with different relationship and ratio of each other's size. In addition, as long as there is no special description in the specification, the number of each component of the utility model is not limited to one, and there may be multiple.

[0104] <Structure of electric valve>

[0105] The electric valve according to the present embodiment includes a driving unit, a speed reduction mechanism as a gear speed reducer, a screw mechanism, and a valve body as a basic structure. The driving unit includes a motor that functions by an excitation function and is composed of a stator and a rotor. The driving unit includes an electric motor.

[0106] The speed reduction mechanism performs gear reduction by inputting the rotational driving force based on the driving part, and outputs the decelerated rotation. That is, in the speed reduction mechanism, the input rotation input from the driving part is decelerated to form the output rotation, and the output rotation is output to the screw mechanism part. The speed reduction mechanism (speed reduction device) includes a planetary gear speed reduction mechanism (planetary gear speed reduction device).

[0107] In addition, the thread mechanism converts the decelerated rotation from the deceleration mechanism, i.e., the output rotation, into a displacement in the axial direction of the thread and outputs it through the action of the thread. The valve body controls the valve opening by utilizing the displacement output in the axial direction of the thread mechanism to make the valve core contact and separate with respect to the valve seat. Figure 1 Each component is described.

[0108] (Driver)

[0109] like Figure 1 As shown, the driving unit of the electric valve 1 according to the present embodiment includes a housing 30 , a motor exciter 2 , and a rotor assembly 50 .

[0110] (case)

[0111] The housing 30 is an airtight container fixed to the valve body 10 and has a topped cylindrical shape. The housing 30 is a topped cylindrical pressure container made of a non-magnetic metal material. Figure 1 The lower end of the housing 30 abuts against the peripheral edge of the receiving member 20 provided on the valve body 10 .

[0112] The housing 30 is fixed to the valve body 10 via the receiving member 20. The valve body 10 has a valve chamber 12 formed at the bottom and a throttle hole 14 extending downward from the bottom of the valve chamber 12. A refrigerant pipe 18A communicating with the side of the valve chamber 12 and a refrigerant pipe 18B communicating with the lower end of the throttle hole 14 are fixed to the valve body 10. The rotor assembly 50 installed inside the housing 30 rotates by supplying a drive signal to the coil 3 of the motor excitation device 2.

[0113] (Motor Excitation Device)

[0114] The motor excitation device 2 is mounted on the outer side of the housing 30 in a removable fitting state relative to the housing 30 through a mounting member 5 formed of a leaf spring. In the motor excitation device 2, the coil 3 constituting the stator of the motor is molded integrally with the resin. The motor excitation device 2 has a resin mold, a coil 3 wound on a winding frame mounted inside the resin mold, and a stator excited by energizing the coil 3, and the coil 3 is connected to an external power source via a circuit 4 and a wire to receive power. Figure 1 The symbols of the resin molds are omitted for ease of observation.

[0115] (Bearings, shafts)

[0116] The bearing 40 is a cross-sectional cap-shaped or disc-shaped bearing having a hole 41 at the center. The bearing 40 is inserted into the inner side of the top of the housing 30 and is arranged on the inner side of the housing 30. The shaft 42 is inserted into the hole 41 of the bearing 40. The rotor assembly 50, which is a permanent magnet type rotor of the stepping motor, is rotatably arranged inside the housing 30 via the shaft 42.

[0117] (Rotor assembly)

[0118] The rotor assembly 50 is rotatably supported in the housing 30. The rotor assembly 50 is a permanent magnet type that is driven to rotate by the motor excitation device 2. The motor excitation device 2 is an excitation device for a stepping motor as an example of an electric motor.

[0119] The rotor assembly 50 is formed into a topped cylindrical shape by a plastic material containing a magnetic material, and is integrally molded with a sun gear component 54 disposed in the center. A sleeve (not shown) extending vertically downward from the center is provided on the sun gear component 54. The sleeve has a through hole 58 for the shaft 42. A sun gear 56, which is a component of the speed reduction mechanism 60, is formed on the outside of the sleeve.

[0120] (Gearbox)

[0121] The gear box 61 is a cylindrical member. The lower portion of the gear box 61 is fitted with the upper portion of the holder 72. The upper portion of the gear box 61 is bent toward the fixed gear 62. The gear box 61 is made of metal or the like.

[0122] The bent portion of the gear box 61 contacts the outer surface of the fixed gear 62 made of resin or the like. In the present embodiment, the fixed gear 62 is fixed to the gear box 61 by riveting. That is, the fixed gear 62 is locked in the bent portion of the gear box 61. The speed reduction mechanism 60 is accommodated in the gear box 61. In addition, the gear box 61 may also be included in the speed reduction mechanism 60.

[0123] (Action of the reduction mechanism)

[0124] In the speed reduction mechanism 60, the sun gear 56 of the rotor assembly 50 functions as an input gear. The planetary gears 65 supported by the planetary gear carrier 64 mesh with the sun gear 56 and with the fixed gear 62 (more precisely, the ring gear (fixed side internal gear) 62A formed on the inner peripheral surface of the fixed gear 62, see Figure 2 ) and the output gear 66 (more precisely, the output side internal gear 66D formed on the inner peripheral surface of the output gear 66, see Figure 2 The entire planetary gear carrier 64 is supported so as to be able to rotate freely on the output gear 66.

[0125] The ring gear 62A and the output side internal gear 66D have different numbers of teeth, but are both configured to mesh with the planetary gear 65. In order to achieve meshing of these components, the misalignment coefficient of the gears of the ring gear 62A and the output side internal gear 66D is set to an appropriate value. When the planetary gear 65 rotates and revolves while meshing with the ring gear 62A 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.

[0126] Therefore, in the speed reduction mechanism 60, the input rotation from the sun gear 56 is decelerated and output to the output gear 66, and as a result, the speed is reduced at a large reduction ratio of, for example, about 50 to 1. Therefore, the rotation speed of the rotor assembly 50 is reduced to, for example, 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 small rotation speed. Therefore, the opening degree of the valve can be controlled with high resolution.

[0127] (Reduction ratio)

[0128] In the speed reduction mechanism 60, the speed reduction ratio is described when the number of teeth of the output side internal gear 66D of the output gear 66 is greater than the number of teeth of the ring gear 62A. When the sun gear 56 rotates together with the rotor assembly 50 in the clockwise (CW) direction by the action of the motor excitation device 2, the planetary gear 65 meshing with the sun gear 56 and the ring gear 62A rotates in the counterclockwise (CCW) direction, in other words, it rotates on its own while revolving around the sun gear 56.

[0129] As a result, the planetary carrier 64 is decelerated and rotates clockwise (CW). The output gear 66 meshing with the planetary gear 65 is driven by the ring gear 62A (see Figure 2 ) and the output side internal gear 66D (refer to Figure 2 ), the gear ratio of the output gear 66 is further reduced in speed and rotated in the clockwise direction (CW). When the numbers of teeth of the sun gear 56, the planetary gears 65, the ring gear 62A of the fixed gear 62, and the output side internal gear 66D of the output gear 66 in the reduction mechanism 60 are set to Z1, Z2, Z3, and Z4, respectively, the output gear ratio of the output gear 66, i.e., the reduction ratio, is expressed by the following formula (1).

[0130] Reduction ratio = [Z4 × (Z1 + Z3)] / [Z1 × (Z4 - Z3)] ... (1)

[0131] Among them, Z3≠Z4

[0132] Furthermore, the above formula (1) can also be expressed as the following formula (2) by dividing the denominator and numerator on the right side by (Z1×Z4).

[0133] Reduction ratio = (1 + Z3 / Z1) / (1 - Z3 / Z4) ... (2)

[0134] The smaller the difference between the number of teeth of the ring gear 62A of the fixed gear 62 and the number of teeth of the output side internal gear 66D of the output gear 66, the larger the reduction ratio can be. Therefore, when it is desired to increase the reduction ratio, for example, when the number of planetary gears is 3, it can be set to [Z4-Z3]=3. In addition, the larger the Z3 / Z1, the larger the reduction ratio can be obtained. Therefore, in order to reduce the number of teeth Z1 of the sun gear 56 and obtain the necessary reduction ratio, the number of teeth Z3 of the ring gear 62A, the number of teeth Z4 of the output side internal gear 66D, and the number of teeth Z2 of the planetary gear 65 are determined respectively.

[0135] For example, when Z1=12, Z2=18, Z3=48, and Z4=54 are set, the output gear ratio of the output gear 66 is a large reduction ratio of 45 / 1. Since the rotation of the rotor assembly 50 is transmitted to the screw shaft 71 at a large reduction ratio of 45 / 1, the valve opening can be finely controlled, that is, with high resolution.

[0136] (Output shaft)

[0137] like Figure 1 As shown, the output shaft 70 is a cylindrical member having a bottomed first hole 70A for receiving the shaft 42 and a second hole 70B (eg, a slot or a slit-like groove) formed on the opposite side of the first hole 70A. Figure 1 As shown, the rotation of the output shaft 70 is transmitted to the shaft 42 by inserting the flat plate-shaped protrusion 71A of the threaded shaft 71 into the second hole 70B.

[0138] (Pipe, Cage)

[0139] Two pipes 18A and 18B are installed in an airtight or liquid-tight manner on the valve body 10. A retainer 72 is provided on the upper side of the valve body 10. In the electric valve 1 involved in this embodiment, the valve body 10 and the retainer 72 are made integrally using the same parts. In addition, in the utility model, it is not limited to this, and the valve body and the retainer can also be made separately using different parts and integrated by welding or the like.

[0140] The retainer 72 is a cylindrical member. The outer diameter of the retainer 72 is smaller than that of the valve body 10, and the outer edge of the valve body 10 is located radially outward of the outer edge of the retainer 72. A shoulder of the valve body 10 is formed at the boundary height between the valve body 10 and the retainer 72.

[0141] (Receiving parts)

[0142] The lower surface of the annular receiving member 20 is welded to the upper surface of the shoulder portion of the valve body 10. The outer portion of the receiving member 20 is located outside the outer edge of the valve body 10.

[0143] The bearing 73 is fitted inside the retainer 72, and the retainer 72 and the bearing 73 are integrated by press-fitting, riveting, etc. The gear box 61 is installed on the upper side of the retainer 72 in a fitted state. A protrusion 71A is provided on the upper part of the threaded shaft 71. The protrusion 71A is inserted into the second hole 70B of the output shaft 70 of the speed reduction mechanism 60. A ball 74 is fixed to the concave part 71B at the lower part of the threaded shaft 71. The rotation of the threaded shaft 71 is converted into a rotation along the same axis as the gear box 61. Figure 1 The thread axial movement is parallel to the center axis X in the valve body, and is transmitted to the valve stem 75 side via the ball 74.

[0144] (Thread mechanism)

[0145] The screw mechanism of the electric valve 1 uses a screw feed mechanism to convert the rotation of the output shaft 70 of the speed reduction mechanism 60 into a linear motion that causes the valve core 76 to contact and separate with respect to the valve seat 17, and transmits it to the valve stem 75. The screw mechanism of this embodiment includes a screw shaft 71. The screw shaft 71 is screwed with a screw formed on the inner surface of the cylindrical bearing 73. In the screw mechanism, the screw shaft 71 is driven.

[0146] Furthermore, the bearing may be formed integrally with the retainer using the same member. When the bearing is formed integrally with the retainer, the output gear 66 (output shaft 70 ) is directly supported by the retainer 72 .

[0147] (Valve body)

[0148] The valve body of this embodiment includes the threaded shaft 71, the ball 74, the ball receiving member 74A, the valve stem 75, and the valve element 76. Alternatively, the valve body may include the valve body 10, the valve chamber 12, and the orifice 14.

[0149] In the valve body of the electric valve 1, the movement of the threaded shaft 71 is transmitted to the valve stem 75 via the ball 74 and the ball receiving member 74A. As a result, the valve element 76 attached to the top end of the valve stem 75 moves along the Figure 1 The valve core 76 moves linearly in the vertical direction (the center axis X direction) in the middle. Therefore, the flow path area between the valve core 76 and the throttle hole 14 is controlled, and as a result, the flow rate of the refrigerant is regulated. In addition, the spring bearing component 26 is installed across the valve stem 75 and the valve body 10. The spring bearing component 26 is described below, which has the function of supporting the lower end of the compression coil spring 24 that applies force to the valve core 76 upward and the function of serving as a sliding guide when the valve core 76 moves up and down.

[0150] (Valve body)

[0151] A valve chamber 12 is formed inside the valve body 10, and a valve seat 17 is formed as a part of the wall surface forming the valve chamber 12. A throttle hole 14 communicating with the valve chamber 12 is formed in the valve body 10. In addition, a pipe 18A communicating with the valve chamber 12 and a pipe 18B communicating with the throttle hole 14 are installed in the valve body 10 in an airtight or liquid-tight manner.

[0152] (Valve stem)

[0153] A valve core 76 is disposed inside the valve chamber 12. The valve core 76 opens and closes an opening formed in the valve seat 17 by contacting and separating with respect to the valve seat 17. That is, the valve core 76 can open and close the opening of the valve seat 17. In order to move the valve core 76, a valve stem 75 connected to the threaded shaft 71 of the threaded mechanism is connected to the valve core 76.

[0154] (Spring bearing parts)

[0155] The spring bearing member 26 is cylindrical. Figure 1 As shown, the spring receiving member 26 includes 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 portion 26C extending horizontally from the edge of the upper end of the large diameter portion 26B. A step portion 26D is formed at the boundary between the small diameter portion 26A and the large diameter portion 26B.

[0156] 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 valve body 10. Figure 1 The lower surface of the valve body 72 contacts the step at the boundary between the valve body 10 and the retainer 72 on the inner side of the valve body 10 . Figure 1The upper surface of the flange-shaped portion 26C in the spring receiving member 26 contacts the lower surface of the bearing 73. The flange-shaped portion 26C is fixed at the inner position of the valve body 10 by being sandwiched between the bearing 73 and the valve body 10. The valve stem 75 is inserted into the inner side of the spring receiving member 26 so as to be slidable.

[0157] like Figure 1 As shown in FIG. 1 , the lower portion of the side surface of the valve stem 75 contacts the inner surface of the small diameter portion 26A. Figure 1 A compression coil spring 24 is arranged between an upper portion of the side surface of the valve stem 75 and an inner side surface of the large diameter portion 26B. Figure 1 The lower coil end of the compression coil spring 24 in the middle contacts the upper surface of the step portion 26D at the boundary between the small diameter portion 26A and the large diameter portion 26B. Figure 1 The upper coil end of the compression coil spring 24 in the valve stem 75 contacts a flange-shaped spring receiving portion 75A provided on the upper portion of the valve stem 75 .

[0158] The ball receiving member 74A of the ball 74 is fixed to the upper end of the valve stem 75 in an inserted state. Figure 1 As shown, the threaded shaft 71 contacts the upper portion of the ball 74. The ball 74 transmits the axial thrust to the valve stem 75 side via the threaded mechanism.

[0159] exist Figure 1 In FIG. 1 , the valve stem 75 is lowered by the output rotation from the speed reduction mechanism 60, and the valve core 76 reaches the lowest point, thereby the electric valve 1 is closed. Figure 1 When the output rotation is reversed from the state illustrated in FIG. 2 , the valve stem 75 is lifted by the urging force of the compression coil spring 24 , and as a result, the electric valve 1 is opened.

[0160] (Special planetary gear reduction mechanism)

[0161] Next, refer to Figure 2 to Figure 7 The speed reduction mechanism 60 involved in the present embodiment is further specifically described. The speed reduction mechanism 60 involved in the present embodiment is a singular planetary gear speed reduction mechanism. In addition, in the present utility model, the speed reduction mechanism is not limited to a singular planetary gear speed reduction mechanism, and can also be other planetary gear speed reduction mechanisms (planetary gear speed reduction devices).

[0162] like Figure 2 As shown, in this embodiment, the speed reduction mechanism 60 can be divided into an upper input region R1 and a lower output region R2 along the axial direction. The input region R1 is provided with the sun gear 56, the first teeth T1 of the planetary gear 65, and the fixed gear 62. The output region R2 is provided with the second teeth T2 of the planetary gear 65 and the output gear 66.

[0163] In input region R1, input rotation from motor exciter 2 as an electric motor is input to sun gear 56 meshing with first teeth T1 of planetary gear 65. In output region R2, output rotation is output from output gear 66 meshing with second teeth T2 of planetary gear 65 to output shaft 70.

[0164] (Fixed gear)

[0165] The fixed gear 62 is, for example, a ring-shaped one formed by molding resin. For example, a flange (not shown) may be formed on the outer periphery of the fixed gear 62, and concave portions (not shown) and convex portions (not shown) may be alternately formed in the circumferential direction for fixing to the upper portion of the gear box 61. Figure 2 As shown, a ring gear 62A is formed on the inner peripheral side of the fixed gear 62 .

[0166] The fixed gear 62 has a different number of teeth from the output gear 66. The diameter of the tooth bottom circle of the fixed gear 62 of this embodiment is, for example, 15 mm or less. In the present invention, the diameter of the tooth bottom circle of the fixed gear 62 is not limited thereto and can be set arbitrarily.

[0167] (Sun gear)

[0168] like Figure 2 As shown, the sun gear 56 is arranged concentrically with the fixed gear 62. The input rotation is input to the sun gear 56. The sun gear 56 is meshed with only the first tooth T1 of the planetary gear 65. Figure 2 In order to facilitate observation, the Figure 1 An illustration of the planetary gear carrier 64 is shown in FIG.

[0169] (Planetary Gear Carrier)

[0170] The planetary gear carrier 64 is formed by molding plastic, for example, and has a pair of disks each having a hole in the center for the shaft 42 to pass through. Three masts and three partitions extending upward are alternately arranged in the circumferential direction on the peripheral edge of the upper surface of the disk. The planetary gear carrier 64 constitutes the speed reduction mechanism 60. The three planetary gears 65 are rotatably supported on the planetary gear carrier 64. For ease of observation, the hole, mast, and partition of the planetary gear carrier 64 are omitted.

[0171] (Output gear)

[0172] like Figure 2As shown, the output gear 66 is a bottomed cylindrical member having a bottom 66A and a wall portion 66B rising from the periphery of the bottom 66A. A hole 66C is formed at the center of the bottom 66A into which the cylindrical portion 70C of the output shaft 70 is pressed. The output gear 66 constitutes a ring gear by forming an output-side internal gear 66D on the inner periphery of the output gear 66. The output gear 66 is provided in the output region R2 and meshes with the second teeth T2.

[0173] (Storage Space)

[0174] like Figure 4 As shown, a storage space S capable of accumulating a fluid is formed inside the output gear 66, which is a cylindrical member with a bottom. The fluid is, for example, a refrigerant that moves from the valve core 76 side to the output gear 66 as the electric valve 1 is used, grease, lubricating oil, refrigeration oil, etc. used for the reduction mechanism 60. In particular, the space inside the second tooth T2 where the sun gear 56 does not exist is a space where no other gears exist even when the planetary gear reduction mechanism is driven, and is suitable for storing grease and lubricating oil.

[0175] In the present embodiment, no openings such as holes are provided in the bottom 66A and the wall 66B, and as a result, it is possible to prevent the fluid from leaking outward from the storage space S. By arranging the bottomed output gear 66 at the lowest stage in the speed reduction mechanism 60, a fluid such as a lubricating fluid can be accumulated in the inner storage space S.

[0176] (Planetary gear)

[0177] The planetary gear 65 includes a plurality of first teeth T1 provided so as to be located in the input region R1 , and a plurality of second teeth T2 provided so as to correspond to the plurality of first teeth T1 and to be located in the output region R2 .

[0178] like Figure 3 As shown, the plurality of first teeth T1 are bilaterally symmetrical about the first center line A1 in a plan view. The first center line A1 is an imaginary line extending radially through the rotation center axis V of the planetary gear 65 and the circumferential center on the first pitch circle C1 of the first tooth T1.

[0179] In addition, if Figure 4 As shown, the plurality of second teeth T2 are symmetrical about the second center line A2 when viewed from above. The second center line A2 is an imaginary line extending radially through the center axis V of the rotation of the planetary gear 65 and the center of the circumference on the second pitch circle C2 of the second tooth T2. Figure 4 , the groove width GT between teeth adjacent to each other in the circumferential direction on the pitch circle CT of the output side internal gear 66D of the output gear 66 is illustrated.

[0180] like Figure 5As shown, the planetary gear 65 is a cylindrical member. A hole 65H is formed in the center of the planetary gear 65, which is rotatably engaged with the mast of the planetary gear carrier 64. The first tooth T1 and the second tooth T2 are provided as a gear portion on the outer periphery of the planetary gear 65. Although not shown in the figure, the upper surface of the planetary gear carrier 64, in which the planetary gear 65 is engaged with each mast, is covered with a washer-shaped plate having a hole in the plate, similar to the plate on the lower surface side. In addition, the planetary gear 65 is rotatably fixed to the planetary gear carrier 64 by pressing the convex portion of the top of the mast and the partition into the hole of the plate.

[0181] In this embodiment, the first teeth T1 and the second teeth T2 are integrally formed of the same material, for example, metal, in a single planetary gear 65. In addition, in the present invention, the first teeth T1 and the second teeth T2 may be separately manufactured and integrated with each other to form a single planetary gear.

[0182] like Figure 5 and Figure 6 As shown in FIG. 1 , the second tooth T2 has a module different from the module of the first tooth T1. In other words, one planetary gear 65 has teeth with different modules. Figure 6 A part that is arranged in two levels in the up and down directions.

[0183] like Figure 7 As shown, in the planetary gear 65 of this embodiment, the first center line A1 and the second center line A2 corresponding to each other overlap when viewed from above. Figure 6 The second teeth T2 are arranged in parallel in the same plane including the central axis V of the planetary gear 65 in the vertical direction. The number of the second teeth T2 is the same as the number of the first teeth T1.

[0184] However, if Figure 7 As shown, the diameter of the second pitch circle C2 of the second tooth T2 is smaller than the diameter of the first pitch circle C1 of the first tooth T1. Therefore, the module of the second tooth T2 is smaller than the module of the first tooth T1. In addition, the full tooth height of the second tooth T2, that is, the tooth height H2 of the second tooth T2, is lower than the full tooth height of the first tooth T1, that is, the tooth height H1 of the first tooth T1. In addition, the second groove width G2 of the second tooth T2 is narrower than the first groove width G1 of the first tooth T1. The groove width is the length of the groove formed between the teeth adjacent to each other in the circumferential direction measured in the circumferential direction.

[0185] In addition, in the present embodiment, the case where the modules of the first tooth T1 and the second tooth T2 are different from each other by changing only the diameter of the pitch circle is exemplified, but the present invention is not limited to this. In the present invention, the modules of the first tooth T1 and the second tooth T2 can be different from each other by changing only the number of teeth or by changing both the number of teeth and the diameter of the pitch circle.

[0186] (Assembly method of electric valve)

[0187] Next, a method for assembling the electric valve according to the present embodiment will be described: First, the fixed gear 62 , the output gear 66 , and the planetary gear 65 are assembled to produce the planetary gear type speed reduction mechanism 60 .

[0188] Specifically, the assembler places the valve body 10 on a workbench for assembly, for example, in a state where the valve body 10 is fixed in advance. Components located on the lower side of the speed reduction mechanism 60, such as the output shaft 70, the threaded shaft 71, the retainer 72, the bearing 73, the ball 74, the ball receiving member 74A, the valve stem 75, and the valve core 76, are assembled inside the valve body 10. In addition, the protrusion 71A of the threaded shaft 71 is engaged with the second hole 70B of the output shaft 70, and the end of the shaft 42 on the output shaft 70 side is not inserted into the first hole 70A of the output shaft 70.

[0189] Next, the assembler arranges the output gear 66 so that the bottom 66A is located at the bottom. In addition, the assembler arranges the hole 66C of the output gear 66 and the first hole 70A of the output shaft 70 concentrically. Next, the assembler overlaps the fixed gear 62 concentrically on the upper side of the output gear 66.

[0190] Next, the assembler uses the side of the second tooth T2 ( Figure 5 The planetary gear 65 supported by the planetary gear carrier 64 is inserted from the upper side of the fixed gear 62 together with the planetary gear carrier 64. Figure 5 As shown, the planetary gear 65 includes first teeth T1 disposed on the upper side and second teeth T2 disposed on the lower side corresponding to the first teeth T1. The second teeth T2 have the same number of teeth as the first teeth T1, and the diameter of the second pitch circle C2 of the second teeth T2 is smaller than the diameter of the first pitch circle C1 of the first teeth T1.

[0191] Then, the assembler meshes the first teeth T1 with the ring gear 62A of the fixed gear 62, and meshes the second teeth T2 with the output-side internal gear 66D of the output gear 66. That is, by inserting the planetary gear 65 into the space inside the fixed gear 62 and the output gear 66 that are integrally configured, the planetary gear 65, the fixed gear 62, and the output gear 66 are meshed successively in time sequence.

[0192] In addition, in the present embodiment, the case where the process of inserting the planetary gear 65 into the space inside the fixed gear 62 and the output gear 66 is performed after the process of integrating the output gear 66 and the fixed gear 62 is illustrated, but in the present invention, the order of the assembly process is not limited to this. In the present invention, the order of the assembly process can be appropriately changed: for example, after the process of inserting the second tooth of the planetary gear 65 into the output gear 66, the process of inserting the first tooth of the planetary gear 65 protruding from the output gear 66 into the fixed gear 62 is performed.

[0193] In addition, the assembler inserts the sun gear component 54 from the upper side of the fixed gear 62 in such a manner that the sun gear 56 meshes with the three planetary gears 65 on the inner side of the planetary gear carrier 64. Through the above series of steps, the planetary gear type reduction mechanism 60 involved in this embodiment can be manufactured. In addition, the assembler can assemble the electric valve 1 involved in this embodiment by installing other components such as the shaft 42 and the housing 30 from the upper side to the manufactured planetary gear type reduction mechanism 60.

[0194] (Effect)

[0195] In the electric valve 1 involved in this embodiment, the module of the first tooth T1 and the module of the second tooth T2 are different from each other. Therefore, the planetary gear type reduction mechanism can be designed without being restricted by the condition of making the module of the first tooth and the module of the second tooth consistent, so the freedom of design of the planetary gear type reduction mechanism can be improved. In addition, similarly, the freedom of design of the electric valve 1 involved in this embodiment can be improved.

[0196] In addition, in the present embodiment, a planetary gear type reduction mechanism can be realized, in particular, a singular planetary gear type reduction mechanism including the fixed gear 62 and the sun gear 56 .

[0197] In addition, in the present embodiment, the degree of freedom in designing a small electric valve 1 in which the diameter of the tooth bottom circle of the fixed gear 62 is 15 mm or less can be increased.

[0198] Furthermore, in the present embodiment, also in the electric valve 1 , the degree of freedom in designing the electric valve 1 can be improved, in particular, because the rotor assembly and the planetary gear type speed reduction mechanism are disposed in the space between the valve body and the housing.

[0199] In addition, in the present embodiment, a storage space S capable of accumulating fluid is formed inside the tubular member. Here, for example, by making the number of teeth of the second teeth T2 of the planetary gear 65 the same as the number of teeth of the first teeth, and making the diameter of the second pitch circle C2 of the second teeth T2 smaller than the diameter of the first pitch circle C1 of the first teeth T1, so that the module of the second teeth T2 is smaller than the module of the first teeth T1, the number of teeth of the output gear 66 meshing with the second teeth T2 can be reduced.

[0200] The diameter of the second teeth T2 decreases, and the volume of the storage space S increases accordingly. For example, when the fluid accumulated in the storage space S is a lubricating fluid, the volume of the lubricating fluid that can be retained in the storage space S increases, thereby improving the lubricity of the electric valve 1.

[0201] In addition, here, for example, when assembling a relatively small planetary gear type reduction mechanism, a plurality of planetary gears are often integrated by being rotatably supported on a planetary gear carrier. Since the planetary gears are rotatable, when the planetary gears are inserted into the output gear or the fixed gear, the position of the teeth closest to the internal teeth of the output gear or the fixed gear is difficult to engage with the internal teeth of the output gear or the fixed gear. In other words, between the teeth of each of the plurality of planetary gears and the internal teeth of the output gear or the fixed gear, the teeth and the grooves cannot mesh while maintaining the original positional relationship.

[0202] Therefore, during insertion, it is necessary to slightly rotate some or all of the plurality of planetary gears while supported by the planetary carrier to change the positional relationship of the planetary gear teeth so that the planetary gear teeth mesh with the internal teeth of the output gear or the fixed gear.

[0203] In particular, when the number of teeth between the first teeth and the second teeth arranged in two stages in the planetary gear is different, each first tooth and each second tooth do not correspond to each other one by one. In other words, in a manner in which the direction of the first center line of the first tooth and the direction of the second center line of the second tooth are randomly arranged, the number of teeth having different relative positional relationships between the first tooth and the second tooth increases. In particular, when the number of teeth in meshing is mutually prime, the relative positional relationships of all teeth between the first tooth and the second tooth are different.

[0204] Therefore, when the number of teeth of the first and second teeth of the planetary gears is different, when the planetary gears are inserted into the output gear or the fixed gear while being supported by the planetary carrier, the work burden of changing the positional relationship of the teeth of the planetary gears is large.

[0205] On the other hand, in the present embodiment, even if the modules of the first teeth T1 and the second teeth T2 are different from each other, the number of teeth of the first teeth T1 and the number of teeth of the second teeth T2 are the same. Therefore, when the planetary gear 65 is inserted into the output gear 66 or the fixed gear 62 while the planetary gear 65 is supported by the planetary gear carrier 64, the burden of the operation of changing the positional relationship of the teeth of the planetary gear 65 can be suppressed compared to the case where the numbers of teeth of the first teeth T1 and the second teeth T2 are different from each other.

[0206] In addition, in the present embodiment, since the number of teeth of the output gear 66 meshing with the second teeth T2 can be reduced, the gap between adjacent teeth in the output gear 66 is increased compared to the case where the number of teeth of the output gear 66 is the same. Therefore, the planetary gear 65 is easily inserted into the output gear 66 and the fixed gear 62.

[0207] In particular, the smaller the electric valve is, the smaller the gap between adjacent teeth in the output gear 66 tends to be. Therefore, it is difficult to insert the planetary gear 65 into the output gear 66 and the fixed gear 62 during assembly. In order to improve the ease of insertion of the planetary gear 65, for example, the following method can be considered: the lower end of the tooth is reduced in such a way that the shape of the lower part of the tooth of the planetary gear 65 decreases as the full tooth height decreases toward the lower side. However, due to the reduction in the volume of the tooth, it is easy to reduce the strength, that is, the durability of the electric valve is reduced. In this embodiment, it is advantageous in that the ease of insertion of the planetary gear 65 can be improved without reducing the volume of the tooth.

[0208] <Other embodiments>

[0209] Although the present invention has been described through the above disclosed embodiments, it should not be understood that the discussion and drawings constituting part of the disclosure limit the present invention. The present invention includes various embodiments not described above, and the technical scope of the present invention is determined only by the technical features of the appropriate scope of protection from the above description.

Claims

1. An electric valve, characterized in that: have: Electric motor; a planetary gear type reduction mechanism, the planetary gear type reduction mechanism having a planetary gear and an output gear, the planetary gear having a first tooth and a second tooth, the first tooth being input with the input rotation of the motor, the second tooth being provided corresponding to the first tooth and having a module different from the module of the first tooth, the output gear meshing with the second tooth and outputting an output rotation obtained by reducing the input rotation; as well as The valve body controls the opening of the valve by rotating the output.

2. The electric valve according to claim 1, characterized in that: The planetary gear type reduction mechanism comprises: a fixed gear having a number of teeth different from the number of teeth of the output gear; and A sun gear is disposed concentrically with the fixed gear and receives the input rotation, and the sun gear meshes with the first teeth of the planetary gears.

3. The electric valve according to claim 2, characterized in that: The diameter of the tooth bottom circle of the fixed gear is less than 15 mm.

4. The electric valve according to any one of claims 1 to 3, characterized in that: have: a valve body having a valve chamber formed therein; a valve seat formed on a portion of a wall surface of the valve chamber and having an opening; a valve core configured to open and close the opening of the valve seat; A valve stem, which enables the valve core to contact and separate from the valve seat; a cylindrical housing mounted on the valve body and forming a space between the housing and the valve body; An excitation device of the motor, the excitation device being mounted on the outer periphery of the housing; a permanent magnet type rotor assembly, the rotor assembly being rotatably supported inside the housing and driven to rotate by the excitation device; and a screw mechanism portion that converts the output rotation from the planetary gear type reduction mechanism into a contact and separation action of the valve core relative to the valve seat and transmits the same to the valve stem, The rotor assembly and the planetary gear type speed reduction mechanism are arranged in the space between the valve body and the housing.

5. The electric valve according to claim 4, characterized in that: The output gear is a bottomed cylindrical member having a bottom and a wall portion rising from the peripheral edge of the bottom. A storage space capable of accumulating a fluid is formed inside the tubular member.

6. The electric valve according to claim 2 or 3, characterized in that: The planetary gear type reduction mechanism is a singular planetary gear type reduction mechanism, When the number of teeth of the sun gear, the number of teeth of the planetary gear, the number of teeth of the ring gear of the fixed gear, and the number of teeth of the output side internal gear of the output gear are respectively set to Z1, Z2, Z3, and Z4, the reduction ratio of the planetary gear type reduction mechanism is expressed by the following formula: Reduction ratio = (1 + Z3 / Z1) / (1 - Z3 / Z4).

7. The electric valve according to claim 6, characterized in that: The Z1, Z2, Z3, and Z4 are set to Z1=12, Z2=18, Z3=48, and Z4=54, respectively.

8. The electric valve according to claim 2 or 3, characterized in that: The planetary gear type reduction mechanism is divided into an upper input area and a lower output area along the axial direction. The sun gear, the first teeth of the planetary gears, and the fixed gear are arranged in the input region, and the second teeth of the planetary gears and the output gear are arranged in the output region. In the input region, the input rotation from the motor is input to the sun gear meshing with the first teeth of the planetary gear, and in the output region, the output rotation is output from the output gear meshing with the second teeth of the planetary gear to the output shaft, The number of the first teeth of the planetary gear is the same as the number of the second teeth.

9. A planetary gear type reduction mechanism, characterized in that: The invention has a planetary gear and an output gear, wherein the planetary gear has a first tooth and a second tooth, wherein the first tooth is input with an input rotation from the outside, the second tooth is provided corresponding to the first tooth and has a module different from the module of the first tooth, and the output gear meshes with the second tooth to output an output rotation in which the input rotation is reduced in speed.

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