Motor-operated valve

Abstract

To provide an electric valve with long service life.SOLUTION: The electric valve includes: a planetary gear-type speed reduction mechanism 6 for reducing rotation speed of a rotor and transmitting the rotation to an output shaft 7, a valve body movable in an axial direction to contact with / separate from a valve seat; and a feed screw mechanism for converting rotational movement of the output shaft into axial movement of the valve body. The planetary gear-type speed reduction mechanism includes: sun gears 611, 621, 631, to which rotational force from the rotor is transmitted; planetary gears 613, 623, 633 engaging with the sun gears; carriers 614, 624, 634 rotatably supporting the planetary gears, respectively; and an annular ring gear 612 engaging with the planetary gears and fixed to the valve body side. Therein, slide contact members 615, 625, 635 are arranged between the sun gears and the carrier. The sun gears are each formed of a first type of raw material and the slide contact members are each formed of a second type of raw material, and the first type of raw material and the second type of raw material are different from each other.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a motor-operated valve, and more particularly to a motor-operated valve that is incorporated in a refrigeration cycle and used to control the flow rate of a fluid such as a refrigerant. [Background technology]

[0002] Conventionally, so-called motor-operated valves that use an electric motor to open and close a valve have been known in which the rotation of a rotor is directly transmitted to a screw mechanism to open and close the valve. There is a demand for such motor-operated valves to be able to open and close the valve under higher load conditions, or to have a higher resolution for the valve opening degree.

[0003] In response to this, the present applicant has proposed an electric valve in which the rotation of the rotor is decelerated by a planetary gear type reduction mechanism and then transmitted to a screw mechanism, as shown in Patent Document 1. In such an electric valve, the torque per unit rotation of the rotor is large, so it can be used even under high load conditions, and the resolution of the valve opening per drive pulse can be increased. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-60466 A Summary of the Invention [Problem to be solved by the invention]

[0005] According to the motor-operated valve of Patent Document 1, in order to suppress wear when the sun gear and the ring gear made of the same resin material slide against each other, a sliding member made of a material different from that of the sun gear is arranged at the axial end of the sun gear. However, sliding between parts made of the same material also occurs in parts other than the sun gear and the ring gear, so even if wear of the sun gear and the ring gear can be suppressed, if other parts wear out, the life of the motor-operated valve cannot be extended. In addition, attempts have been made to increase the reduction ratio by providing a multi-stage planetary gear type reduction mechanism in the motor-operated valve, but in such motor-operated valves, the torque increases toward the lower stages, and wear due to sliding between the sun gear and the carrier on the lower stages becomes a problem.

[0006] An object of the present invention is to provide a motor-operated valve having a long life. [Means for solving the problem]

[0007] In order to achieve the above object, the motor-operated valve according to the present invention comprises: a valve body having a valve seat; a motor having a rotor; a planetary gear type reduction mechanism that reduces the rotation speed of the rotor and transmits the reduced speed to an output shaft; a valve body that is axially movable toward and away from the valve seat; a feed screw mechanism for converting a rotational movement of the output shaft into an axial movement of the valve body; In a motor-operated valve comprising: The planetary gear reduction mechanism includes: a sun gear to which rotational force from the rotor is transmitted; a planetary gear meshing with the sun gear; A carrier that rotatably supports the planetary gear; a ring gear that is meshed with the planetary gear and fixed to the valve body; Equipped with A sliding contact member is disposed between the sun gear and the carrier, the sun gear is made of a first material, the sliding contact member is made of a second material, and the first material and the second material are different from each other; The motor-operated valve has a planetary gear type reduction mechanism having a plurality of stages, the carrier of the final stage planetary gear reduction mechanism is connected to the output shaft, a final stage sliding contact member is disposed between the sun gear of the final stage planetary gear reduction mechanism and the output shaft, The sun gear and the output shaft of the final stage planetary gear reduction mechanism are formed from the first type of material, and the final stage sliding contact member is formed from the second type of material. Effect of the Invention

[0008] According to the present invention, a motor-operated valve having a long life can be provided. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a vertical cross-sectional view showing a motor-operated valve according to a first embodiment. [Diagram 2] FIG. 2 is a diagram showing the periphery of a speed reduction mechanism of the motor-operated valve according to the first embodiment. [Diagram 3] FIG. 3 is an enlarged vertical cross-sectional view showing a part of a speed reduction mechanism of a motor-operated valve according to a modified example. [Figure 4] FIG. 4 is a vertical sectional view showing the motor-operated valve according to the second embodiment. [Diagram 5] FIG. 5 is a diagram showing the periphery of a speed reduction mechanism of the motor-operated valve according to the second embodiment. [Figure 6] FIG. 6 is an enlarged vertical cross-sectional view showing a part of a speed reduction mechanism of a motor-operated valve according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, a motor-operated valve according to an embodiment of the present invention will be described with reference to the drawings. In the following description of the embodiment and the comparative example, parts and members having the same functions are given the same reference numerals, and repeated description of parts and members given the same reference numerals will be omitted.

[0011] (Definition of dissimilar materials and axial direction) Here, if "adhesive wear" occurs when two components slide against each other, the materials from which the components are made are called homogeneous materials. Also, "dissimilar materials" refers to materials that are not homogeneous, that is, if "adhesive wear" does not occur when two components slide against each other, the material of one component corresponds to a dissimilar material with respect to the material of the other component. Examples of dissimilar materials include materials from different categories when any material is classified into categories such as metal, resin, ceramic, glass, etc. Also, "axial direction" here refers to the direction of the central axis of the shaft. In this specification, the upper side refers to the stator side, and the lower side refers to the main valve body side relative to the stator.

[0012] [First embodiment] Fig. 1 is a vertical cross-sectional view showing a motor-operated valve 1 according to a first embodiment. Fig. 2 is a diagram showing the periphery of a speed reduction mechanism 6 of the motor-operated valve 1 according to this embodiment.

[0013] The electric valve 1 mainly comprises a valve body 2, a can 3, a valve element 4 arranged in the internal space of the valve body 2, a stepping motor 5 that generates a rotational torque to drive the valve element 4, a reduction mechanism 6 arranged inside the can 3 that reduces the rotational torque of the stepping motor 5 and transmits the driving force to the valve element 4 via an output shaft 7, and a feed screw mechanism 9.

[0014] The valve body 2 defines a valve chamber VC therein. The valve body 2 has a vertical opening 21 extending from above along the axis L toward the valve chamber VC, a first horizontal opening 22 extending from the side toward the valve chamber VC in a direction perpendicular to the axis L, second horizontal openings 23 formed alternately parallel to the axis of the first horizontal openings 22, and a communication opening 24 connecting the valve chamber VC to the inner end of the second horizontal opening 23. A hollow cylindrical valve seat member 30 is fitted into the communication opening 24. The inner periphery of the valve seat member 30 forms an orifice passage, and its upper end constitutes a valve seat 31. A filter 25 for filtering foreign matter in the refrigerant is arranged in the second horizontal opening 23.

[0015] A cylindrical spring receiving member 26 is fitted into the vertical opening 21 of the valve body 2, and a first male thread 26a formed on the outer periphery of the upper end of the spring receiving member 26 is screwed into a first female thread 21a formed on the inner periphery of the vertical opening 21, thereby fastening and fixing the spring receiving member 26 to the valve body 2. The spring receiving member 26 has a central opening 26b penetrating in the direction of the axis L, an annular groove 26c formed on the upper surface, a communication hole 26d communicating between the lower surface of the spring receiving member 26 and the annular groove 26c, and a small cylindrical portion 26e formed by the center of the annular groove 26c protruding upward.

[0016] A hollow cylindrical base material 27 is fitted into the vertical opening 21 of the valve body 2 so that its lower end abuts against the upper end of the spring receiving member 26 and the small cylindrical portion 26e is fitted into the inner circumference. The base material 27 is fastened and fixed to the valve body 2 by a second male thread 27a formed on the outer circumference of the upper end of the base material 27 screwing into a first female thread 21a formed on the inner circumference of the vertical opening 21. The base material 27 has a flange portion 27b whose lower surface abuts against the upper surface of the valve body 2 and a reduced diameter cylindrical portion 27c extending upward. The inner circumference of the annular plate 28 is fitted into the outer peripheral step of the reduced diameter cylindrical portion 27c by press fitting. The outer circumference of the annular plate 28 is fixed to the lower end of the thin-walled tubular body 64 by welding or brazing.

[0017] The stepping motor 5 has a stator 55 consisting of a yoke 51, a bobbin 52, a coil 53, a resin molded cover 54, etc., and a rotor 57 disposed inside the can 3 so as to be rotatable relative to the can 3 and having a rotor support member 56 fixed to its upper inside. The stator 55 is fitted and fixed to the outside of the can 3. The lower end of the resin molded cover 54 is fitted to the outer periphery of the flange portion 27b of the base material 27.

[0018] The reduction mechanism 6 has a first-stage reduction section 61, a second-stage reduction section 62, and a third-stage reduction section 63, which are coaxially arranged and connected in series on the inner circumferential side of the rotor 57. In this specification, it is assumed that the rotational torque is first input from the rotor to the first-stage reduction section 61, and the rotational torque is output from the output shaft 7 connected to the final-stage reduction section, i.e., the third-stage reduction section 63. Furthermore, the reduction sections being "connected in series" means that the rotational torque output from the N-th stage reduction section is input to the (N+1)-th stage reduction section.

[0019] As shown in FIG. 2, the first stage reduction section 61 has a sun gear 611 formed integrally with the rotor support member 56, an upper part of a fixed ring gear (ring gear) 612 held and fixed by a thin-walled cylindrical body 64 fixed to the valve body 2 via the substrate 27, planetary gears 613 arranged between the sun gear 611 and the fixed ring gear 612 and meshing with them, and a carrier 614 that supports the planetary gear 613 for free rotation, thereby forming a first stage planetary gear type reduction mechanism.

[0020] An annular first washer 615 is disposed between the lower surface of the sun gear 611 and the upper surface of the carrier 614. In this embodiment, the sun gear 611 (i.e., the rotor support member 56) and the carrier 614 are made of resin, and the first washer 615 is made of metal, that is, they are formed from different materials.

[0021] The second stage reduction section 62 has a sun gear 621 formed integrally on a shaft extending downward along the axis L from the carrier 614 of the first stage reduction section 61, an intermediate portion of the fixed ring gear 612, a planetary gear 623 arranged between the sun gear 621 and the fixed ring gear 612 and meshing with them, and a carrier 624 that supports the planetary gear 623 for free rotation, and together these form a second stage planetary gear type reduction mechanism.

[0022] An annular second washer 625 is disposed between the lower surface of the sun gear 621 and the upper surface of the carrier 624. In this embodiment, the sun gear 621 (i.e., the carrier 614) and the carrier 624 are made of resin, and the second washer 625 is made of metal, that is, they are formed from different materials.

[0023] The third stage reduction section 63 has a sun gear 631 formed integrally on an axis extending downward along the axis L from the carrier 624 of the second stage reduction section 62, a lower part of the fixed ring gear 612, a planetary gear 633 arranged between the sun gear 631 and the fixed ring gear 612 and meshing with them, and a carrier 634 that supports the planetary gear 633 for free rotation, and together these form a third stage planetary gear type reduction mechanism.

[0024] The upper end of the output shaft 7 is fitted and fixed in a central opening formed in the center of the carrier 634, and the two are capable of rotating integrally.

[0025] An annular third washer 635 is disposed between the lower surface of the sun gear 631 and the upper surface of the output shaft 7 penetrating the carrier 624. In this embodiment, the sun gear 631 (i.e., the carrier 624) and the output shaft 7 are made of resin, and the third washer 635 is made of metal, that is, they are formed of different materials. Note that the planetary gears 613, 623, and 633 may be made of metal or resin. In this embodiment, the first washer 615 and the second washer 625 constitute sliding contact members, and the third washer 635 constitutes a sliding contact member or a final stage sliding contact member.

[0026] In this embodiment, the first-stage reduction section 61, the second-stage reduction section 62, and the third-stage reduction section 63 share the fixed ring gear 612, which allows the reduction mechanism 6 to be made compact.

[0027] The lower end of the shaft member 8 is fitted into a hole 72 formed in the center of the upper end of the output shaft 7. As shown in FIG. 1, the upper end of the shaft member 8 is inserted into the center hole of the support member 81. The support member 81 has an outer diameter substantially equal to the inner diameter of the can 3, and is disposed on the upper side of the rotor support member 56 in contact with the can 3. The shaft member 8 penetrates the rotor support member 56, the first washer 615, the carrier 614, the second washer 625, the carrier 624, and the third washer 635, and holds them so that they can rotate relative to each other. That is, the shaft member 8 is used in common for the first-stage reduction unit 61, the second-stage reduction unit 62, and the third-stage reduction unit 63. The rotor 57 itself is held by the support member 81 and the like so as not to move up and down inside the can 3, and the positional relationship with the stator 55 fitted and fixed to the outside of the can 3 is always maintained constant.

[0028] 1, the feed screw mechanism 9 includes a cylindrical bearing 91, a screw shaft 92, and balls 93. The cylindrical bearing 91 has a lower end portion fixed to the inner periphery of the upper end side of the base material 27.

[0029] The cylindrical bearing 91 supports the lower surface of the carrier 634 at its upper end surface, and the output shaft 7 is inserted into the hollow upper part of the cylindrical bearing 91 so as to be rotatable relative to the carrier 634. Therefore, it is preferable that the cylindrical bearing 91 and the carrier 634 are made of different materials. A third male screw portion 92a formed on the outer periphery of the screw shaft 92 is screwed into a third female screw portion 91a formed on the inner periphery of the lower part of the cylindrical bearing 91. In addition, a convex portion 92b, which is a flat driver portion provided on the screw shaft 92, is inserted into a slit-shaped recessed portion 7b formed on the lower end of the output shaft 7, and the output shaft 7 and the screw shaft 92 are configured to be movable relative to each other in the axial direction but rotate together. A recessed portion is formed at the lower end of the screw shaft 92, and a ball 93 is fixed to the screw shaft 92 while being fitted into the recessed portion.

[0030] The rotation of the screw shaft 92 is converted into axial movement by the screw action between it and the cylindrical bearing 91, and is transmitted to the valve body 4 via balls 93 and a ball receiving member 94. The ball receiving member 94 is fitted and fixed into a valve body holding member 95 which is press-fitted into the upper end of the valve body 4 to form an integrated unit. Note that a recess may be provided in the screw shaft 92, and a protrusion to be inserted into the recess may be provided on the output shaft 7.

[0031] In order to remove backlash between the third female thread portion 91a and the third male thread portion 92a when the screw shaft 92 is moved in the valve opening direction in the feed screw mechanism 9, a coil spring 70 that urges the valve body 4 in the valve opening direction via the valve body holding member 95 is provided inside the base material 27. The upper end of the coil spring 70 abuts against the lower surface of the flange of the valve body holding member 95, and the upper end of the coil spring 70 abuts against the upper end of the small cylindrical portion 26e of the spring receiving member 26.

[0032] The shaft portion 41 of the valve body 4 is fitted into the central opening 26b of the spring receiving member 26 so as to be slidable in the direction of the axis L, and the umbrella portion 42 connected to the lower end of the shaft portion 41 has a tapered surface 43 on its outer periphery. The tapered surface 43 is capable of being seated on the valve seat 31.

[0033] The valve body 4 is constantly biased in the valve opening direction (towards the feed screw mechanism 9) by the spring force of the coil spring 70 which is held in a compressed state, and when the valve body 4 is pushed down in the valve closing direction by the driving force from the feed screw mechanism 9, the valve body 4 is pushed down against the spring force of the coil spring 70, causing the tapered surface 43 to seat on the valve seat 31 and close the orifice.

[0034] Since the screw shaft 92 can rotate at a minute rotation speed relative to the rotation of the rotor 57 and the axial displacement of the screw shaft 92 corresponding to that rotation can be controlled with minute displacement, the axial position of the valve element 4 relative to the valve seat 31 can be positioned with high resolution by the reduction mechanism 6 and the flow passage area between the tapered surface 43 and the valve seat 31 can be controlled with high precision, thereby enabling the flow rate of the passing refrigerant to be adjusted with high precision. In other words, high-resolution valve opening control is achieved. When the feed screw mechanism 9 is operated in the valve opening direction, the spring force of the coil spring 70 causes the valve shaft 60 to move in response to the upward movement of the screw shaft 92.

[0035] In the motor-operated valve shown in FIG. 1, the refrigerant is introduced into the can 3 through the communication hole 26d of the spring receiving member 26 and the gap between the members.

[0036] (Operation of motor-operated valve) The operation of the motor-operated valve 1 according to this embodiment will be described. The terminal 59 arranged inside the resin molded cover 54 is connected to the coil 53. When power is supplied from an external power source through the terminal 59 via a connector connected to the external power source (not shown), the stator of the stepping motor 5 generates a magnetic force. The rotor 57 is rotationally driven based on this magnetic force, generating a rotational force in a predetermined direction. This rotational force is transmitted to the reduction mechanism 6 via the rotor support member 56.

[0037] 2, in the first stage reduction section 61 of the reduction mechanism 6, the planetary gear 613 revolves around the axis L along the fixed ring gear 612 upon receiving a rotational force transmitted from a sun gear 611 integral with the rotor support member 56, whereby the carrier 614 rotates around the axis L while being decelerated at a first reduction ratio. At this time, a relative rotation occurs between the sun gear 611 and the carrier 614, but since a first washer 615 made of a different material and disposed between the sun gear 611 and the carrier 614 is interposed between them, wear due to the relative rotational sliding between the sun gear 611 and the carrier 614 and the first washer 615 can be suppressed.

[0038] In the second stage reduction section 62, the planetary gear 623 revolves around the axis L along the fixed ring gear 612 upon receiving a rotational force transmitted from the sun gear 621 integral with the carrier 614, whereby the carrier 624 rotates around the axis L while being decelerated at a second reduction ratio. At this time, a relative rotation occurs between the sun gear 621 and the carrier 624, but since the second washer 625 made of a different material and disposed between the sun gear 621 and the carrier 624 is interposed between them, wear due to the relative rotational sliding between the sun gear 621 and the carrier 624 and the second washer 625 can be suppressed.

[0039] In the third-stage reduction section 63, the planetary gear 633 revolves around the axis L along the fixed ring gear 612 upon receiving a rotational force transmitted from a sun gear 631 integral with the carrier 624, whereby the carrier 634 rotates around the axis L while being decelerated at a third reduction ratio. At this time, a relative rotation occurs between the sun gear 631 and the output shaft 7, but since a third washer 635 made of a different material and disposed between the sun gear 631 and the output shaft 7 is interposed between them, wear due to relative rotational sliding between the sun gear 631 and the output shaft 7 and the third washer 635 can be suppressed. When the carrier 634 slides on the sun gear 631 instead of the output shaft 7, the carrier 634 is made of resin.

[0040] In this way, the rotational force of the rotor 57 is transmitted to the output shaft 7 after being decelerated by the speed reducing mechanism 6. Furthermore, the rotational movement of the output shaft 7 is converted into the upward movement of the screw shaft 92 via the feed screw mechanism 9, so that the valve element 4 biased by the spring force of the coil spring 70 follows the upward movement of the screw shaft 92, and the tapered surface 43 of the valve element 4 moves away from the valve seat 31 to allow the passage of the refrigerant. As a result, the refrigerant that has entered the valve chamber VC through the orifice from the second side opening 23 passes through the first side opening 22 and flows out to the outside of the motor-operated valve 1. Note that the refrigerant may also flow from the first side opening 22 through the valve chamber VC to the second side opening 23.

[0041] On the other hand, when power with reverse characteristics is supplied from an external power source via terminal 59 in response to a valve-closing signal, the valve body 4 moves down against the spring force of coil spring 70, and tapered surface 43 seats on valve seat 31 to prevent the passage of refrigerant. This blocks the flow of refrigerant between the first side opening 22 and the second side opening 23.

[0042] In the above embodiments, the sun gear 611 and the carrier 614, the sun gear 621 and the carrier 624, the sun gear 631 and the output shaft 7 are made of resin, and the first washer 615, the second washer 625, and the third washer 635 are made of metal. Alternatively, the sun gear 611 and the carrier 614, the sun gear 621 and the carrier 624, the sun gear 631 and the output shaft 7 may be made of metal, and the first washer 615, the second washer 625, and the third washer 635 may be made of resin.

[0043] If washers are not used, the materials of the components of each reduction section can be set as in the following setting examples (1) and (2). This allows parts made of different materials to slide against each other, suppressing wear.

[0044] Setting example (1) Sun gear 611 of first stage reduction section 61: Resin Carrier 614 of first stage reduction unit 61 (and sun gear 621 of second stage reduction unit 62): Metal Carrier 624 of second stage reduction section 62 (and sun gear 631 of third stage reduction section 63): Resin Output shaft 7 (or carrier 634 of third stage reduction unit 63): Metal

[0045] Setting example (2) Sun gear 611 of first stage reduction section 61: Metal Carrier 614 of first stage reduction section 61 (and sun gear 621 of second stage reduction section 62): Resin Carrier 624 of second stage reduction unit 62 (and sun gear 631 of third stage reduction unit 63): Metal Output shaft 7 (or carrier 634 of third-stage reduction section 63): Resin

[0046] (Modification) 3 is an enlarged longitudinal sectional view of a portion of the reduction gear mechanism of the motor-operated valve according to the modified example. Here, the shaft member 8, the carrier 614A of the first stage reduction unit, and the first washer 615A are shown. If the shaft member 8 is made of metal and the first washer 615A is made of the same metal, there is a risk that the shaft member 8 and the first washer 615A will be worn due to sliding between them.

[0047] Therefore, in this modification, the inner diameter of the first washer 615A is made larger than the outer diameter of the shaft member 8, and the first washer 615A is arranged and fixed coaxially with the through-hole 614Aa of the carrier 614A through which the shaft member 8 passes. The first washer 615A can be positioned and fixed to the carrier 614A by using adhesive or insert molding.

[0048] According to this modification, a gap is formed between the outer periphery of the shaft member 8 and the inner periphery of the first washer 615A, so that they do not slide against each other, and wear of both can be suppressed. In order to arrange the first washer 615A coaxially with the through hole 614Aa, for example, an annular recess having the same diameter as the first washer 615A may be formed on the upper surface of the carrier 614A, and the first washer 615A may be fitted into the annular recess. Alternatively, an annular protrusion surrounding the through hole 614Aa may be formed on the upper surface of the carrier 614A, and the inner periphery of the first washer 615A may be fitted into the annular protrusion.

[0049] The above-mentioned configuration is not limited to the first washer 615A, but can also be applied to the second washer and the third washer in the same manner.

[0050] [Second embodiment] Fig. 4 is a vertical cross-sectional view showing a motor-operated valve 1B according to a second embodiment. Fig. 5 is a diagram showing the periphery of a speed reduction mechanism 6B of the motor-operated valve 1B according to this embodiment. The motor-operated valve 1B of this embodiment differs from the above-mentioned embodiment only in the configurations of the output shaft 7B, the shaft member 8B, and the speed reduction mechanism 6B. Other configurations are the same as those of the above-mentioned embodiment, so repeated explanations will be omitted.

[0051] In this embodiment, the output shaft 7B does not have a hole on its upper surface into which the shaft member fits, and the upper surface is flat. The shaft member 8B does not pass through the reduction mechanism 6B, and abuts against the carrier 614B of the first-stage reduction section 61B. The reduction mechanism 6B has a first-stage reduction section 61B, a second-stage reduction section 62B, and a third-stage reduction section 63B, which are coaxially arranged and connected in series on the inner circumferential side of the rotor 57.

[0052] As shown in FIG. 5, the first stage reduction section 61B has a sun gear 611B formed integrally with the rotor support member 56, an upper part of a fixed ring gear 612, a planetary gear 613B arranged between the sun gear 611B and the fixed ring gear 612 and meshing with them, and a carrier 614B that supports the planetary gear 613B for free rotation, and together these form a first stage planetary gear type reduction mechanism.

[0053] An annular first washer 615B is disposed between the lower surface of the sun gear 611B and the upper surface of the carrier 614B. In this embodiment, the sun gear 611B and the carrier 614B are made of resin, and the first washer 615B is made of metal, that is, they are formed from different materials. This makes it possible to suppress wear caused by relative rotation and sliding between the sun gear 611B and the carrier 614B and the first washer 615B. Although the shaft member 8B does not penetrate the carrier 614B, the multiple planetary gears 613B supported by the carrier 614B revolve while meshing with the fixed ring gear 612, so that the carrier 614B rotates around the axis line L without swinging.

[0054] The second stage reduction section 62B has a sun gear 621B formed integrally on a shaft extending downward along the axis L from the carrier 614B of the first stage reduction section 61B, an intermediate portion of the fixed ring gear 612, a planetary gear 623B arranged between the sun gear 621B and the fixed ring gear 612 and meshing with them, and a carrier 624B that supports the planetary gear 623B for free rotation, and together these form a second stage planetary gear type reduction mechanism.

[0055] Between the lower surface of the sun gear 621B and the upper surface of the carrier 624B, a disk-shaped second disk 625B with flat surfaces is disposed. In this embodiment, the sun gear 621B and the carrier 624B are made of resin, and the second disk 625B is made of metal, that is, they are formed from different materials. This makes it possible to suppress wear caused by relative rotation and sliding between the sun gear 621B and the carrier 624B and the second disk 625B. Although the shaft member 8B does not pass through the carrier 624B, the multiple planetary gears 623B revolve while meshing with the fixed ring gear 612, so that the carrier 624B rotates around the axis line L without swinging.

[0056] The third stage reduction section 63B has a sun gear 631B formed integrally on a shaft extending downward along the axis L from the carrier 624B of the second stage reduction section 62B, a lower part of the fixed ring gear 612, a planetary gear 633B arranged between the sun gear 631B and the fixed ring gear 612 and meshing with them, and a carrier 634B that supports the planetary gear 633B for free rotation, and together these form a third stage planetary gear type reduction mechanism.

[0057] The upper end of the output shaft 7B is fitted and fixed in a central opening formed in the center of the carrier 634B, and the two are capable of rotating integrally.

[0058] Between the lower surface of the sun gear 631B and the upper surface of the output shaft 7B, a third disk 635B having flat surfaces is disposed. In this embodiment, the sun gear 631B and the output shaft 7B are made of resin, and the third disk 635B is made of metal, that is, they are formed from different materials. This makes it possible to suppress wear caused by relative rotation and sliding between the sun gear 631B and the output shaft 7B and the third disk 635B. Although the shaft member 8B does not penetrate the carrier 634B, the multiple planetary gears 633B revolve while meshing with the fixed ring gear 612, so that the carrier 634B rotates around the axis L without swinging.

[0059] In the above embodiment, the sun gear 611B and the carrier 614B, the sun gear 621B and the carrier 624B, the sun gear 631B and the output shaft 7B are made of resin, and the first washer 615B, the second disk 625B and the third disk 635B are made of metal. In contrast, the sun gear 611B and the carrier 614B, the sun gear 621B and the carrier 624B, the sun gear 631B and the output shaft 7B may be made of metal, and the first washer 615B, the second disk 625B and the third disk 635B may be made of resin. In addition, when the first washer 615B is made of resin, it may be disc-shaped like the other washers and the lower end of the shaft member 8 may be abutted against it. In this embodiment, the first washer 615B and the second disk 625B constitute the sliding contact member, and the third disk 635B constitutes the sliding contact member or the final stage sliding contact member.

[0060] According to this embodiment, the sun gear and the carrier or the output shaft can be displaced in the direction perpendicular to the axis by an amount equivalent to the clearance between the components, thereby making it possible to suppress localized wear.

[0061] (Modification) 6 is an enlarged longitudinal sectional view of a part of the reduction gear mechanism of the motor-operated valve according to the modified example. Here, the shaft member 8B, the carrier 614C of the first stage reduction unit, and the first washer 615C are shown. If the shaft member 8B, which is the same as in the second embodiment, is made of metal and the first washer 615C is made of the same kind of metal, there is a risk that the shaft member 8B and the first washer 615C will be worn due to sliding between them.

[0062] Therefore, in this modification, the first washer 615C is annular, the inner diameter of which is larger than the outer diameter of the shaft member 8, and is arranged and fixed to the carrier 614C so as to be coaxial with the shaft member 8B. The first washer 615C can be positioned and fixed to the carrier 614C by using adhesive or insert molding.

[0063] According to this modification, a gap is formed between the outer periphery of the shaft member 8B and the inner periphery of the first washer 615C, so that they do not slide against each other and wear of both can be suppressed. In order to arrange the first washer 615C coaxially with the shaft member 8B, for example, an annular recess having the same diameter as the first washer 615C may be formed on the upper surface of the carrier 614C, and the first washer 615C may be fitted into the annular recess. Alternatively, an annular protrusion surrounding the shaft member 8B may be formed on the upper surface of the carrier 614C, and the inner periphery of the first washer 615C may be fitted into the annular protrusion.

[0064] In the above-described embodiment, the reduction mechanism has three planetary gear mechanisms, but it may have two or four or more planetary gear mechanisms. In addition, at least one of the planetary gear mechanisms may be a paradox planetary gear mechanism.

[0065] This specification includes the disclosure of the following inventions. (Invention A) a valve body having a valve seat; a motor having a rotor; a planetary gear type reduction mechanism that reduces the rotation speed of the rotor and transmits the reduced speed to an output shaft; a valve body that is axially movable toward and away from the valve seat; a feed screw mechanism for converting a rotational movement of the output shaft into an axial movement of the valve body; In a motor-operated valve comprising: The planetary gear reduction mechanism includes: a sun gear to which rotational force from the rotor is transmitted; a planetary gear meshing with the sun gear; A carrier that rotatably supports the planetary gear; a ring gear that is meshed with the planetary gear and fixed to the valve body; Equipped with A sliding contact member is disposed between the sun gear and the carrier, The sun gear is made of a first material, the sliding contact member is made of a second material, and the first material and the second material are different from each other. A motor-operated valve.

[0066] (Invention B) A shaft member passes through the sun gear, the sliding contact member, and the carrier. The motor-operated valve of the present invention A.

[0067] (Invention C) The sliding contact member is disk-shaped. The motor-operated valve of the present invention A.

[0068] (Invention D) The motor-operated valve has a planetary gear type reduction mechanism having a plurality of stages, the plurality of carriers of the multi-stage planetary gear reduction mechanism are all made of the first material, The carrier of the N-stage planetary gear reduction mechanism is integral with the sun gear of the (N+1)-stage planetary gear reduction mechanism. The motor-operated valve according to any one of Inventions A to C,

[0069] (Invention E) the carrier of the final stage planetary gear reduction mechanism is joined to the output shaft, a final stage sliding contact member is disposed between the sun gear of the final stage planetary gear reduction mechanism and the output shaft, The sun gear and the output shaft of the final stage planetary gear reduction mechanism are formed from the first type of material, and the final stage sliding contact member is formed from the second type of material. The motor-operated valve of the present invention D.

[0070] (Invention F) A shaft member passes through the sun gear and the final stage sliding member of the final stage planetary gear type reduction mechanism, and the shaft member is fitted into a hole formed in the output shaft. The motor-operated valve of the present invention D.

[0071] (Invention G) The final stage sliding contact member is disk-shaped. The motor-operated valve of the present invention D.

[0072] (Invention H) One of the first material and the second material is a resin, and the other is a metal. The motor-operated valve according to any one of Inventions A to G.

[0073] (Invention I) a valve body having a valve seat; a motor having a rotor; a planetary gear type reduction mechanism that reduces the rotation speed of the rotor and transmits the reduced speed to an output shaft; a valve body that is axially movable toward and away from the valve seat; a feed screw mechanism for converting a rotational movement of the output shaft into an axial movement of the valve body; In a motor-operated valve comprising: The planetary gear reduction mechanism includes: a sun gear to which rotational force from the rotor is transmitted; a planetary gear meshing with the sun gear; A carrier that rotatably supports the planetary gear; a ring gear that is meshed with the planetary gear and fixed to the valve body; a shaft member that passes through the sun gear and the carrier and rotatably holds them; Equipped with a plurality of the planetary gear type reduction mechanisms are provided, and the shaft member is used in common to the plurality of the planetary gear type reduction mechanisms; an annular washer is disposed between the sun gear and the carrier so that the shaft member passes through the washer; the sun gear is made of a resin material, and the washer and the shaft member are made of a metal material, The inner diameter of the washer is larger than the outer diameter of the shaft member, and the washer is fixed to the carrier such that a gap or a part of the carrier is interposed between the shaft member and the washer. A motor-operated valve. [Explanation of symbols]

[0074] 1,1C Motor-operated valve 2 Valve body 3 Can 4 Valve body 5 Stepping motor 6,6B reduction mechanism 7 Output shaft 8 Shaft member 9. Lead screw mechanism 61,61B 1st stage reduction section 611,611B Sun gear 612 Fixed Ring Gear 613,613B Planetary gear 614,614B Carrier 615,615B First washer 62,62B 2nd stage reduction section 621,621B Sun gear 623,623B Planetary gear 624,624B Carrier 625 Second washer 625B 2nd disc 63,63B 3rd stage reduction section 631,631B Sun gear 633,633B Planetary gear 634,634B Carrier 635 3rd washer 635B 3rd disc

Claims

1. a valve body having a valve seat; a motor having a rotor; a planetary gear type reduction mechanism that reduces the rotation speed of the rotor and transmits the reduced speed to an output shaft; a valve body that is axially movable toward and away from the valve seat; a feed screw mechanism for converting a rotational movement of the output shaft into an axial movement of the valve body; In a motor-operated valve comprising: The planetary gear reduction mechanism includes: a sun gear to which rotational force from the rotor is transmitted; a planetary gear meshing with the sun gear; A carrier that rotatably supports the planetary gear; a ring gear that is meshed with the planetary gear and fixed to the valve body; Equipped with A sliding contact member is disposed between the sun gear and the carrier, the sun gear is made of a first material, the sliding contact member is made of a second material, and the first material and the second material are different from each other; The motor-operated valve has a planetary gear type reduction mechanism having a plurality of stages, the carrier of the final stage planetary gear reduction mechanism is connected to the output shaft, a final stage sliding contact member is disposed between the sun gear of the final stage planetary gear reduction mechanism and the output shaft, the sun gear and the output shaft of the final stage planetary gear reduction mechanism are formed from the first type of material, and the final stage sliding contact member is formed from the second type of material, A motor-operated valve.

2. A shaft member passes through the sun gear, the sliding contact member, and the carrier.

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

3. The sliding contact member is disk-shaped.

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

4. A shaft member passes through the sun gear and the final stage sliding member of the final stage planetary gear type reduction mechanism, and the shaft member is fitted into a hole formed in the output shaft.

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

5. The final stage sliding contact member is disk-shaped.

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

6. One of the first material and the second material is a resin, and the other is a metal. The motor-operated valve according to any one of claims 1 to 5.

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