Electric valve and planetary gear type speed reducing mechanism

Abstract

The utility model provides a novel technology capable of increasing the reduction ratio in an electric valve and a planetary gear type reduction mechanism. In n (n is a natural number of 2 or more) planetary gears (a first planetary gear (65A), a second planetary gear (65B), and a third planetary gear (65C)), a predetermined phase difference (a first phase difference (D1), a second phase difference (D2)) is formed between a first tooth (T1) and a second tooth (T2) of each planetary gear. The difference between the phase difference of one of the planetary gears adjacent in the circumferential direction and the phase difference of the other planetary gear is (1 / n) * the pitch width (P) of the second teeth (T2).

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 in which the three basic axes consisting of the input shaft, the output shaft and the fixed shaft all have the same rotation axis as the central axis of the device, although it is not an electric valve. In a planetary gear type reduction mechanism, the smaller the difference in the number of teeth between the fixed gear and the output gear, the greater the reduction ratio can be obtained.

[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] In this specification, 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 number of first teeth is the same as the number of second teeth.

[0010] In addition, in this specification, in the gear of the planetary gear, when viewed from above, the imaginary line extending in the radial direction through the center axis of rotation of the planetary gear and the center of the circumferential direction on the pitch circle of the tooth is referred to as the center line of the tooth. In addition, in the output side internal gear corresponding to the planetary gear, when viewed from above, the imaginary line extending in the radial direction through the center axis of rotation of the planetary gear type speed reduction mechanism and the center of the circumferential direction on the pitch circle of the groove between the teeth is referred to as the center line of the groove.

[0011] In addition, when viewed from above, the state in which the center line of the first tooth overlaps the center line of the second tooth is called "same phase" or "no phase difference is formed", and the state in which the center line of the first tooth is offset from the center line of the second tooth is called "different phase" or "formation of phase difference".

[0012] Here, consider the teeth of n planetary gears and the grooves of the output side internal gears meshing with the n planetary gears respectively. n is a natural number greater than 2. In all meshing positions of the n planetary gears, the state in which the center line of the teeth of the planetary gears overlaps with the center line of the groove of the output side internal gear is the case where the number of grooves of the output side internal gear, that is, the number of teeth of the output side internal gear is a value n×k that is an integer multiple of n. k is a natural number. Therefore, in the differential gear mechanism, the minimum value of the difference in the number of teeth of the fixed gear and the number of teeth of the output gear cannot be less than n.

[0013] In this regard, Patent Documents 1 and 2 do not include any study on making the difference in the number of teeth smaller than n, and as a result, an increase in the reduction ratio cannot be achieved. Utility Model Content

[0014] In view of the above, the utility model provides a new technology capable of increasing the reduction ratio in an electric valve and a planetary gear type reduction mechanism.

[0015] Technical means for solving technical problems

[0016] The electric valve involved in the first embodiment comprises: an electric motor; a planetary gear reduction mechanism, the planetary gear reduction mechanism having an output gear and n (n: a natural number greater than 2) planetary gears, the planetary gear having a first tooth and a second tooth, the first tooth being input with an input rotation of the electric motor, the second tooth being provided corresponding to the first tooth, the output gear meshing with the second tooth and outputting an output rotation obtained by reducing the input rotation; and a valve body portion, the valve body portion controlling the opening of the valve through the output rotation, wherein, among the n planetary gears, a diameter of a first pitch circle of the first tooth is the same as a diameter of a second pitch circle of the second tooth, the number of teeth of the first tooth is the same as the number of teeth of the second tooth, a predetermined phase difference is formed between the first tooth and the second tooth in each of the planetary gears, and a difference between the phase difference of one of the planetary gears adjacent in the circumferential direction and the phase difference of the other of the planetary gears is (1 / n)×the pitch width of the second tooth.

[0017] Here, when the difference in the number of teeth between the fixed gear and the output gear is 1, at the meshing position of the second tooth, the phase difference between the center line of the second tooth and the center line of the groove of the output gear increases sequentially by (1 / n)×the pitch width of the output gear in the order in which the planetary gears are arranged in the circumferential direction.

[0018] In the electric valve involved in the first embodiment, the sum of the phase differences of the respective planetary gears among the n planetary gears is preliminarily formed to correspond to a distance of one pitch width of the output gear. Therefore, the minimum value of the difference in the number of teeth between the number of teeth of the fixed gear meshing with the first teeth and the number of teeth of the output gear meshing with the second teeth can be set to 1. Therefore, the difference in the number of teeth can be made smaller than n, and as a result, the reduction ratio of the planetary gear type reduction mechanism can be increased.

[0019] The second method is that in the electric valve involved in the first method, the planetary gear 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 which is concentrically arranged with the fixed gear and is input with the input rotation, and the sun gear meshes with the first tooth of the planetary gear.

[0020] In the second aspect, in particular, a planetary gear type reduction mechanism including a fixed gear and a sun gear can be realized.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] The planetary gear reduction mechanism involved in the fifth embodiment has an output gear and n (n: a natural number greater than 2) planetary gears, the n planetary gears respectively having a first tooth and a second tooth, the first tooth being input with an input rotation from the outside, the second tooth being arranged corresponding to the first tooth, the output gear meshing with the second tooth, and outputting an output rotation reduced by the input rotation, and in the n planetary gears, the diameter of the first pitch circle of the first tooth is the same as the diameter of the second pitch circle of the second tooth, the number of teeth of the first tooth is the same as the number of teeth of the second tooth, a predetermined phase difference is formed between the first tooth and the second tooth in each of the planetary gears, and the difference between the phase difference of one of the planetary gears adjacent to each other in the circumferential direction and the phase difference of the other planetary gear is (1 / n)×the pitch width of the second tooth.

[0026] In the planetary gear type speed reduction mechanism according to the fifth aspect, the speed reduction ratio can be increased similarly to the case of the electric valve according to the first aspect.

[0027] Effect of utility model

[0028] According to the electric valve of the present invention, a new technology capable of increasing the reduction ratio in the electric valve and the planetary gear type reduction mechanism can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] Figure 6 It is a plan view for explaining the planetary gear of the singular planetary gear type reduction mechanism according to the present embodiment.

[0035] Explanation of symbols

[0036] 1 Electric valve

[0037] 2 Motor excitation device (motor)

[0038] 3 coils

[0039] 4 Circuit

[0040] 5Mounting parts

[0041] 10 Valve body

[0042] 12 Valve chamber

[0043] 14 throttle holes

[0044] 17 Valve seat

[0045] 18A, 18B piping

[0046] 20 Bearing parts

[0047] 24 Compression coil spring

[0048] 26 Spring bearing parts

[0049] Trail 26A

[0050] 26B large diameter part

[0051] 26C flange

[0052] 26D step part

[0053] 30 Shell

[0054] 40 bearings

[0055] 41 holes

[0056] 42 Axis

[0057] 50 rotor assembly

[0058] 54 sun gear parts

[0059] 56 Sun gear

[0060] 58 through holes

[0061] 60 planetary gear reduction mechanism

[0062] 61 Gear Box

[0063] 62 Fixed Gear

[0064] 62A ring gear

[0065] 64 planetary gear carrier

[0066] 64A hole

[0067] 64B Mast

[0068] 64C Next Door

[0069] 64D board

[0070] 65A first planetary gear

[0071] 65B Second planetary gear

[0072] 65C third planetary gear

[0073] 65H hole

[0074] 66 Output gear

[0075] 66A bottom

[0076] 66B wall

[0077] 66C hole

[0078] 66D Output side internal gear

[0079] 70 Output shaft

[0080] 70A first hole

[0081] 70B second hole

[0082] 70C cylindrical part

[0083] 71 threaded shaft

[0084] 71A protrusion

[0085] 71B concave part

[0086] 72 cage

[0087] 73 bearings

[0088] 74 goals

[0089] 74A ball bearing parts

[0090] 75 valve stem

[0091] 75A spring bearing

[0092] 76 valve core

[0093] A1 First Center Line

[0094] A2 Second Center Line

[0095] C1 first pitch circle

[0096] C2 second pitch circle

[0097] D1 first phase difference

[0098] D2 second phase difference

[0099] P pitch width

[0100] R1 input area

[0101] R2 output area

[0102] T1 first tooth

[0103] T2 second tooth

[0104] Center axis of V planetary gear

[0105] X center axis. DETAILED DESCRIPTION

[0106] 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.

[0107] <Structure of electric valve>

[0108] 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.

[0109] 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).

[0110] 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.

[0111] (Driver)

[0112] 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 .

[0113] (case)

[0114] 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 .

[0115] 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.

[0116] (Motor Excitation Device)

[0117] 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.

[0118] (Bearings, shafts)

[0119] 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.

[0120] (Rotor assembly)

[0121] 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.

[0122] 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.

[0123] (Gearbox)

[0124] 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.

[0125] 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.

[0126] (Action of the reduction mechanism)

[0127] In the speed reduction mechanism 60, the sun gear 56 of the rotor assembly 50 functions as an input gear. The planetary gears supported by the planetary gear carrier 64 mesh with the sun gear 56 and with the fixed gear 62 (more precisely, the ring gear 62A (fixed side internal gear) 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 ) are engaged. Figure 1 The cross-sectional view of FIG. 6 illustrates the first planetary gear 65A and the second planetary gear 65B. The entire planetary carrier 64 is supported on the output gear 66 so as to be rotatable.

[0128] The ring gear 62A and the output side internal gear 66D have different numbers of teeth, but are both configured to mesh with the first planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C. 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 first planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C rotate and revolve 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.

[0129] 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.

[0130] (Reduction ratio)

[0131] 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 first planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C meshing with the sun gear 56 and the ring gear 62A rotate in the counterclockwise (CCW) direction, in other words, they rotate on their own while revolving around the sun gear 56.

[0132] As a result, the planetary gear carrier 64 is decelerated and rotates clockwise (CW). The output gear 66 (see FIG. 1 ) meshes with the first planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C. Figure 2 ) Based on the ring gear 62A (refer to Figure 2 ) and the output side internal gear 66D, is further decelerated and rotated in the clockwise direction (CW). When the numbers of teeth of the sun gear 56, the planetary gears (the first planetary gear 65A, the second planetary gear 65B, the third planetary gear 65C), the ring gear 62A of the fixed gear 62, and the output side internal gear 66D of the output gear 66 in the speed reduction mechanism 60 are respectively set to Z1, Z2, Z3, and Z4, the output gear ratio of the output gear 66, that is, the reduction ratio, is expressed by the following formula (1).

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

[0134] Among them, Z3≠Z4.

[0135] 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).

[0136] Reduction ratio = (1 + Z3 / Z1) / (1 - Z3 / Z4) ... (2)

[0137] 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 gears (first planetary gear 65A, second planetary gear 65B, third planetary gear 65C) are determined respectively.

[0138] 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.

[0139] (Output shaft)

[0140] 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.

[0141] (Pipe, Cage)

[0142] 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.

[0143] 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.

[0144] (Receiving parts)

[0145] 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.

[0146] 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.

[0147] (Thread mechanism)

[0148] 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.

[0149] 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 .

[0150] (Valve body)

[0151] 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.

[0152] 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.

[0153] (Valve body)

[0154] 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.

[0155] (Valve stem)

[0156] 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.

[0157] (Spring bearing parts)

[0158] 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.

[0159] 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 1 The 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.

[0160] 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 .

[0161] 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 1As 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.

[0162] 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.

[0163] (Special planetary gear reduction mechanism)

[0164] Next, refer to Figure 2 to Figure 6 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).

[0165] 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 planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C, respectively, and the fixed gear 62. The output region R2 is provided with the second teeth T2 of the first planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C, respectively, and the output gear 66.

[0166] In the input region R1, the input rotation from the motor excitation device 2 as an electric motor is input to the sun gear 56 meshing with the first teeth T1 of the first planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C. In addition, in the output region R2, the output rotation is output to the output shaft 70 from the output gear 66 meshing with the second teeth T2 of the first planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C.

[0167] (Fixed gear)

[0168] 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 .

[0169] 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.

[0170] (Sun gear)

[0171] like Figure 2 As shown in FIG. 1 , 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 meshes only with the first teeth T1 of the first planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C. Figure 2 In order to facilitate observation, the Figure 1 An illustration of the planetary gear carrier 64 is shown in FIG.

[0172] (Planetary Gear Carrier)

[0173] like Figure 6 As shown, the planetary gear carrier 64 is formed by molding plastic, for example, and has a pair of disks each having a hole 64A at the center for the shaft 42 to pass through. Three masts 64B and three partitions 64C 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. Three first planetary gears 65A, second planetary gears 65B, and third planetary gears 65C are rotatably supported on the planetary gear carrier 64.

[0174] (Output gear)

[0175] like Figure 2 As 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.

[0176] (Planetary gear)

[0177] like Figure 2 As shown, the first planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C include a plurality of first teeth T1 disposed so as to be located in the input region R1 and a plurality of second teeth T2 disposed 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 symmetrical about the first center line A1 when viewed from above. Figure 6As shown, the first center line A1 is an imaginary line extending in the radial direction through the center axis V of each of the first planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C 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. Figure 6 As shown, the second center line A2 is an imaginary line extending radially through the center axis V of rotation of each of the first planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C and the circumferential center on the second pitch circle C2 of the second tooth T2.

[0180] like Figure 5 As shown, the first planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C are cylindrical components. A hole 65H is formed at the center of the first planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C, which is rotatably engaged with the mast 64B of the planetary gear carrier 64. The first teeth T1 and the second teeth T2 are provided as gear parts at the outer periphery of the first planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C.

[0181] like Figure 6 As shown in the figure, the upper surface of the planetary gear carrier 64, in which the first planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C are fitted to each mast 64B, is covered with a washer-shaped plate having a plate hole 64A, similarly to the plate 64D on the lower surface side. In addition, by pressing the convex parts of the top of the mast 64B and the partition wall 64C into the holes of the plate, the first planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C are rotatably fixed to the planetary gear carrier 64.

[0182] In this embodiment, the first teeth T1 and the second teeth T2 are integrally formed in a single planetary gear using the same material, for example, metal. In addition, in the present invention, the first teeth T1 and the second teeth T2 may be separately manufactured and then integrated with each other to form a single planetary gear.

[0183] like Figure 5 and Figure 6 As shown, in the present embodiment, in the three first planetary gears 65A, the second planetary gears 65B, and the third planetary gears 65C, the diameter of the first pitch circle C1 of the first tooth T1 is the same as the diameter of the second pitch circle C2 of the second tooth T2. In addition, the number of teeth of the first tooth T1 is the same as the number of teeth of the second tooth T2. Therefore, the pitch width P of the first planetary gear 65A, the pitch width P of the second planetary gear 65B, and the pitch width P of the third planetary gear 65C are the same.

[0184] However, in the present embodiment, a phase difference is formed between the first center line A1 and the second center line A2 of each of the first planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C. That is, a predetermined phase difference is formed between the first tooth T1 and the second tooth T2. In addition, the difference between the phase difference of one of the first planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C adjacent in the circumferential direction and the phase difference of the other planetary gear is (1 / 3)×the pitch width P of the second tooth T2.

[0185] Specifically, the phase difference is 0 (zero) at the first planetary gear 65A. In addition, the first phase difference D1 is formed at the second planetary gear 65B, and the second phase difference D2 is formed at the third planetary gear 65C. The first phase difference D1 is (1 / 3)×the pitch width P of the second tooth T2. In addition, the second phase difference D2 is (2 / 3)×the pitch width P of the second tooth T2.

[0186] In other words, in the second planetary gear 65B and the third planetary gear 65C, in one planetary gear, the portions where the tooth tops face in different directions from each other are located. Figure 5 In the utility model, the difference between the phase difference of one of the planetary gears adjacent in the circumferential direction and the phase difference of the other planetary gear refers to the value obtained by subtracting the phase difference smaller than the other from the value of the phase difference larger than the other among the respective phase differences of the two planetary gears adjacent in the circumferential direction.

[0187] In addition, regarding the number n of planetary gears, in this embodiment, an example of n=3 is described, but in the present invention, the value of n is not limited to this. Even if the value of n is any natural number greater than 2, the present invention can be applied. Among the n planetary gears, the difference between the first planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C adjacent in the circumferential direction is set to (1 / n)×the pitch width P of the second tooth T2.

[0188] In addition, regarding the phase difference, in the present embodiment, the phase difference of the first planetary gear 65A is set to 0 (zero), the first phase difference D1 of the second planetary gear 65B is set to (1 / 3)×the pitch width P of the second tooth T2, and the second phase difference D2 of the third planetary gear 65C is set to (2 / 3)×the pitch width P of the second tooth T2. However, in the present invention, the setting of the phase difference is not limited to this, and can be appropriately changed.

[0189] For example, when there are three planetary gears, the phase difference of the first planetary gear 65A may be set to (1 / 6)×the pitch width P of the second tooth T2, the phase difference of the second planetary gear 65B may be set to (3 / 6)×the pitch width P of the second tooth T2, and the phase difference of the third planetary gear 65C may be set to (5 / 6)×the pitch width P of the second tooth T2. The difference between the first planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C adjacent to each other in the circumferential direction is (1 / 3)×the pitch width P of the second tooth T2.

[0190] (Effect)

[0191] In the electric valve 1 involved in the present embodiment, in the three first planetary gears 65A, the second planetary gear 65B, and the third planetary gear 65C, the diameter of the first pitch circle C1 of the first tooth T1 is the same as the diameter of the second pitch circle C2 of the second tooth T2. In addition, the number of teeth of the first tooth T1 is the same as the number of teeth of the second tooth T2. In addition, a predetermined phase difference is formed between the first tooth T1 and the second tooth T2 in one of the second planetary gears 65B and the third planetary gear 65C. In addition, the difference between the phase difference of one of the planetary gears 65A, the second planetary gear 65B, and the third planetary gear 65C adjacent in the circumferential direction and the phase difference of the other planetary gear is (1 / n)×the pitch width P of the second tooth T2.

[0192] Here, when the difference in the number of teeth between the fixed gear 62 and the output gear 66 is 1, at the meshing position of the second tooth T2, the phase difference between the second center line A2 of the second tooth T2 and the center line of the groove of the output gear 66 increases sequentially by (1 / 3)×the pitch width of the output gear in the order in which the first planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C are arranged in the circumferential direction.

[0193] In the present embodiment, the sum of the phase differences between the second center line A2 of each of the second teeth T2 of the first planetary gear 65A, the second planetary gear 65B, and the third planetary gear 65C and the center line of the groove of the output gear 66 is preliminarily formed to correspond to a distance of one pitch width of the output gear 66. Therefore, the minimum value of the difference in the number of teeth between the number of teeth of the fixed gear 62 meshing with the first teeth T1 and the number of teeth of the output gear 66 meshing with the second teeth T2 can be set to 1. Therefore, the difference in the number of teeth can be made smaller than n, and as a result, the reduction ratio of the planetary gear type reduction mechanism can be increased. In addition, the reduction ratio of the electric valve 1 involved in the present embodiment can also be increased.

[0194] Furthermore, it can be seen from the above formula (1) or formula (2) that in addition to reducing the difference in the number of teeth between the fixed gear 62 and the output gear 66, it is also possible to consider increasing the number of teeth of one of the fixed gear 62 and the output gear 66 to increase the reduction ratio. In the case of a relatively small electric valve, the outer dimensions of the fixed gear 62 and the output gear 66 are often limited. Therefore, if the number of teeth is to be increased, the size of each tooth needs to be miniaturized.

[0195] However, if the size of each tooth is reduced, it is difficult to ensure the durability of the tooth. In this embodiment, in addition to increasing the reduction ratio, the electric valve can be reduced in size without increasing the number of teeth of the fixed gear 62 and the output gear 66, which is advantageous.

[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] <Other embodiments>

[0200] Although the present invention has been described through the above disclosed embodiments, it should not be understood that the discussion and drawings constituting a part of the present 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 an output gear and n planetary gears, where n is a natural number greater than or equal to 2, the planetary gear having a first tooth and a second tooth, the first tooth being input with an input rotation of the motor, the second tooth being provided corresponding to 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 a valve body part, the valve body part controlling the opening of the valve by rotating the output, Among the n planetary gears, The diameter of the first pitch circle of the first tooth is the same as the diameter of the second pitch circle of the second tooth, The number of teeth of the first teeth is the same as the number of teeth of the second teeth, A preset phase difference is formed between the first tooth and the second tooth in each of the planetary gears, and a difference between the phase difference of one of the circumferentially adjacent planetary gears and the phase difference of the other planetary gear is (1 / n)×the pitch width of the second tooth.

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 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).

6. The electric valve according to claim 5, characterized in that: The Z1, Z2, Z3, and Z4 are set to Z1=12, Z2=18, Z3=48, and Z4=54, respectively.

7. 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 each of the n planetary gears, and the fixed gear are arranged in the input region, and the second teeth of each of the n 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 each of the n planetary gears, and in the output region, the output rotation is output to the output shaft from the output gear meshing with the second teeth of each of the n planetary gears.

8. A planetary gear type reduction mechanism, characterized in that: An output gear and n planetary gears, where n is a natural number greater than or equal to 2, each of the n planetary gears has a first tooth and a second tooth, the first tooth receives an input rotation from the outside, the second tooth is provided corresponding to the first tooth, the output gear meshes with the second tooth, and outputs an output rotation obtained by reducing the input rotation. Among the n planetary gears, The diameter of the first pitch circle of the first tooth is the same as the diameter of the second pitch circle of the second tooth, The number of teeth of the first teeth is the same as the number of teeth of the second teeth, A preset phase difference is formed between the first tooth and the second tooth in each of the planetary gears, and a difference between the phase difference of one of the circumferentially adjacent planetary gears and the phase difference of the other planetary gear is (1 / n)×the pitch width of the second tooth.

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