Motor-operated valve

Abstract

Motor-operated valve (10) comprising: an engine (20); a base portion (15) formed at one end of a stator (11) of the motor (20); a linear motion shaft (50) screwed into a rotor (40) of the motor (20) and supported by the base portion (15) such that the linear motion shaft (50) can move linearly and cannot rotate; a valve port (18) formed in the base portion (15); a valve element (60) arranged at one end of the linear motion shaft (50) and opening and closing the valve port (18); an intermediate member (35) arranged between the rotor (40) and the stator (11); a first contact area (42A, 42T) on the rotor (40) and a second contact area (15T, 35T) on the stator (11) and on the intermediate member (35), wherein the first contact area (42A, 42T) is formed on a rotary screw cylinder (42) of the rotor (40) and the second contact area (15T, 35T) is formed on the intermediate member (35) and on the base area (15), and wherein the first contact area (42A, 42T) and the second contact area (15T, 35T) contact each other in a rotational axis direction of the rotor (40); and a rotor biasing means (36, 58) which biases the rotor (40) in the rotation axis direction such that the first contact portion (42A, 42T) and the second contact portion (35T) are pressed against each other.

Description

TECHNICAL FIELD

[0001] The present invention relates to a motor-operated valve having a motor as a drive source. STATE OF THE ART

[0002] As a conventional motor-operated valve, a motor-operated valve is known in which a linear motion shaft having a valve element at a tip end is driven by a motor (for example, see Patent Literature 1). Another known motor-operated valve includes an internally threaded member in a rotor, an externally threaded member on a shaft, and a non-circular shaft portion at an intermediate portion of the shaft with the externally threaded member. By separating the rotor and the shaft, the workload of a threaded portion between the internally threaded member and the externally threaded member is reduced (Patent Literature 2). Other valves are known from Patent Literatures 3 to 5. DOCUMENTS FROM THE PRIOR ART PATENT DOCUMENTS Patent Document 1: Japanese Unexamined Patent Application Publication No. JP H10-169821A (paragraph

[0007] and Fig. 1) Patent Document 2: Japanese Patent Laid-Open Publication JP 2016-65595 A Patent Document 3: Japanese Patent Laid-Open Publication JP 2016-89870A Patent Document 4: Japanese Patent Laid-Open Publication JP 2006-10 004 A Patent Document 5: Japanese Patent Application Laid-Open No. US 2013 / 0 263 955 A1 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0003] Unfortunately, in the conventional motor-driven valve described above, a rotor rattles relative to a stator and consequently a vibration noise is generated.

[0004] The present invention is made in view of the foregoing circumstances and has an object to provide a motor-driven valve capable of reducing vibration noise. MEANS FOR SOLVING THE INVENTION

[0005] To achieve the above object, a motor-operated valve according to the present invention comprises a motor, a base portion formed at one end of a stator of the motor, a linear motion shaft screwed into a rotor of the motor and supported by the base portion such that the linear motion shaft can move linearly and cannot rotate, a valve port formed in the base portion, a valve element disposed at one end of the linear motion shaft and opening and closing the valve port, an intermediate member disposed between the rotor and the stator, a first contact portion on the rotor, and a second contact portion on the stator and the intermediate member,wherein the first contact portion is formed on a rotary screw cylinder of the rotor and the second contact portion is formed on the intermediate member and the base portion, and wherein the first contact portion and the second contact portion contact each other in a rotational axis direction of the rotor, and a rotor biasing means that biases the rotor in the rotational axis direction such that the first contact portion and the second contact portion are pressed against each other. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side cross-sectional view of a motor-operated valve according to a first embodiment of the present invention. Fig. 2 is a side cross-sectional view of the motor-operated valve in a state where a valve port is open. Fig. 3 is a horizontal cross-sectional view in the vicinity of a shaft support element. Fig. 4 is a side cross-sectional view in the vicinity of a valve element component. Fig. 5 is a side cross-sectional view in the vicinity of a rotor receiving area. Fig. 6 is a side cross-sectional view in the vicinity of a rotor receiving area according to a variant. Fig. 7 is a side cross-sectional view in the vicinity of the rotor receiving area according to the variant. Fig. 8 is a side cross-sectional view in the vicinity of the rotor receiving area according to a variant. MODES FOR CARRYING OUT THE INVENTION [First Embodiment]

[0006] The first embodiment of the present invention will be described below with reference to Fig. 1 to 5. As described in Fig. 1, a motor-operated valve 10 of the present embodiment includes a stator 11, a rotor 40 rotatably received inside the stator 11, and a linear motion shaft 50 that linearly moves inside the stator 11 by the rotation of the rotor 40.

[0007] The stator 11 is formed by fixing a stator-side field portion 13 to the outside of a vertically extending sleeve 12. The stator-side field portion 13 is formed in the shape of an annular ring and includes electromagnetic coils 13A arranged in a row.

[0008] The sleeve 12 is formed of an upper cylindrical portion 14 and a lower cylindrical portion 15 (which corresponds to a "base portion" in the present invention), and the upper cylindrical portion 14 and the lower cylindrical portion 15 are arranged coaxially with each other. The upper cylindrical portion 14 is formed in the shape of a cylinder having substantially the same diameter as a whole, and an opening in its upper surface is hermetically sealed with a lid member 23. The above-described stator-side field portion 13 is fixed to a lower end portion of the upper cylindrical portion 14. The sleeve 12, the lid member 23, and the stator-side field portion 13 constitute the "stator main body" in the present invention.

[0009] As in Fig. 1, the lower cylindrical portion 15 has therein a valve element linear movement space 15X extending from a lower end portion to an intermediate portion, a rotor receiving portion 15Y located above the valve element linear movement space 15X and having a larger diameter than that of the valve element linear movement space 15X, and an upper-end receiving portion (receiving portion at an upper end) 15Z located above the rotor receiving portion 15Y and having a larger diameter than that of the rotor receiving portion 15Y. Among them, a lower end portion of the upper cylindrical portion 14 is attached to the upper-end receiving portion 15Z, and thus the upper cylindrical portion 14 and the lower cylindrical portion 15 are coupled to each other.The upper cylindrical portion 14 and the lower cylindrical portion 15 are welded to each other in a state where the lower end surface (lower end surface) of the upper cylindrical portion 14 abuts against an annular step portion 15D which is the inner surface of the upper-end receiving portion 15Z, and where a flange 15F extending sideways from the upper end of the lower cylindrical portion 15 contacts the lower surface of the stator-side field portion 13.

[0010] A valve seat member 17 is fitted into an opening portion 16 on the lower end side of the lower cylindrical portion 15. The valve seat member 17 is formed in the shape of a cylinder, and its upper end opening is a valve port 18. Additionally, a side portion opening 15B, which is laterally open, is formed in the lower cylindrical portion 15 at a position near the lower end. A first flow path R1 is connected to the valve seat member 17, and a second flow path R2 is connected to the side portion opening 15B.

[0011] The valve port 18 is opened and closed by a valve element 60 provided at the end tip of the linear motion shaft 50. The valve element 60 is formed in the shape of a truncated cone whose diameter decreases toward the end tip portion, and, as shown in Fig. 1, the valve element 60 is received from above in the valve port 18, contacts a valve seat 19 and thereby closes the valve port 18 with the result that the flow is regulated or sealed. And, as shown in Fig. 2, the valve element 60 moves upward to open the valve port 18, and consequently the flow between the first flow path R1 and the second flow path R2 becomes possible.

[0012] The linear motion shaft 50 with the valve element 60 is supported such that the linear motion shaft 50 can move linearly and cannot rotate with respect to the lower cylindrical portion 15. More specifically, as shown in Fig. 1 and Fig. 3, an intermediate part of the linear motion shaft 50 in a vertical direction is formed into a sliding shaft portion 50B whose cross section is shaped like a letter D, and is received by a shaft support member 25 attached to the upper end portion of the valve element linear motion space 15X in the lower cylindrical portion 15. The shaft support member 25 is formed substantially in the shape of a cylinder, has a shaft receiving hole 25D in the shape of a letter D corresponding to the cross section of the sliding shaft portion 50B in the shape of a letter D, and thereby regulates the rotation of the linear motion shaft 50.

[0013] As in Fig. 4, the shaft support member 25 includes an upper member 25A and a lower member 25B. The upper member 25A has a smaller diameter than that of the lower member 25B and is received inside the lower member 25B. At the upper end of the upper member 25A, a flange 25F is provided which extends sideways, and the lower surface of the flange 25F contacts the upper end of the lower member 25B. On the other hand, at a position of the lower member 25B near the lower end, a protruding annular plate 25H is provided which extends inward and which opposes the lower end surface of the upper member 25A. The shaft receiving opening 25D, the cross section of which is formed in the shape of the letter D, is formed in the upper member 25A.

[0014] On the peripheral portion of a receiving portion 15G which receives the shaft support member 25 in the lower cylindrical portion 15, as shown in Fig. 3, two communication holes 15H are formed, and thus the pressures of the upper and lower spaces separated by the shaft support member 25 are made substantially equal.

[0015] As in Fig. As shown in Fig. 1, the rotor 40 is formed by fixing a rotor-side field portion 41 having magnetic properties to the outside of a cylindrical rotary screw cylinder 42. A stepping motor 20, which corresponds to a "motor" in the present invention, is mainly composed of the rotor-side field portion 41 and the stator-side field portion 13, and the driving pattern of the electromagnetic coils 13A in the stator-side field portion 13 changes, with the result that the rotor-side field portion 41 is controlled to be positioned at a predetermined rotational position. The motor-side field portion 41 is arranged upward from a position of the rotary screw cylinder 42 near the lower end, and the lower end portion of the rotary screw cylinder 42 in the rotor 40 is accommodated in the rotor accommodation portion 15Y of the stator 11.

[0016] The rotary screw cylinder 42 is formed in the shape of a cylinder with both ends open, and an internal thread portion 42N is formed on the inner side of the position near the lower end. A male thread portion 50N is formed on the outer surface above the slide shaft portion 50B in the linear motion shaft 50, and the male thread portion 50N is screwed into the internal thread portion 42N of the rotary screw cylinder 42.

[0017] The rotor 40 rotates with respect to the stator 11 in a state where the rotor 40 is positioned in the axial direction by a positioning mechanism described later. In accordance with this rotation, the linear motion shaft 50, which is non-rotatably supported on the lower cylindrical portion 15 of the stator 11, screw-moves into the rotary screw cylinder 42, and consequently, the linear motion position of the valve element 60 changes.

[0018] In the motor-operated valve 10, components described below are provided to regulate the rotation amount of the rotor 40. That is, as shown in Fig. 1, a guide shaft 30 suspended from the cover member 23 is provided in the stator 11. A spiral guide 31 is fixed to the guide shaft 30. The spiral guide 31 is formed by spirally winding wires around a lower portion of the guide shaft 30.

[0019] A stop ring 32 is engaged with the spiral guide 31. The stop ring 32 is formed in the shape of a ring held in a part of a gap between the wires of the spiral guide 31 that are adjacent to each other in the axial direction, and has a stop arm 32A extending sideways. On the inner surface of the rotary screw cylinder 42 of the rotor 40, ring contact portions 42S, 42S (in Fig. 1, only the ring contact portion 42S is shown on the back side) are formed, which are arranged above the internal thread portion 42N so as to extend in the vertical direction and sandwich the stopper arm 32A therebetween. When the rotor 40 rotates, the stopper ring 32 is pressed by the ring contact portions 42S, rotated relative to the spiral guide 31, moved up and down, and becomes non-rotatable when it moves toward the upper end portion or the lower end portion of the spiral guide 31. In this way, the rotation amount of the rotor 40 is controlled.

[0020] Next, the positioning mechanism of the rotor 40 will be described. As shown in Fig. 1, a pressing member 35, which corresponds to an "intermediate member" in the present invention, is provided between the lid member 23 and the rotor 40 in the upper cylindrical portion 14 of the stator 11. The pressing member 35 includes a main plate portion 35A formed in the shape of an annular plate curved downward and a cylindrical support portion 35B projecting upward from its inner edge. The pressing member 35 is supported by inserting the guide shaft 30 through the interior of the cylindrical support portion 35B, so that the pressing member 35 can move linearly and rotate. In other words, in the present embodiment, the guide shaft 30, which regulates the rotation amount of the rotor 40, is also used for supporting the pressing member 35.

[0021] A tapered surface 35T is formed in the outer peripheral portion of the main plate portion 35A in the pressing member 35, and the tapered surface 35T contacts a top-end opening edge (an opening edge at an upper end) 42A of the rotary screw cylinder 42 in the rotor 40. The top-end opening edge 42A is chamfered to form a small tapered surface. The spiral guide 31 of the guide shaft 30 is arranged at a position lower than the pressing member 35.

[0022] In addition, a compression coil spring 36 (corresponding to a "rotor biasing means" and an "elastic member" in the present invention) is interposed between the pressing member 35 and the lid member 23 so as to be sandwiched therebetween. The pressing member 35 is biased downward by the compression coil spring 36 so as to press the rotor 40 onto the inner surface of the rotor receiving portion 15Y. Accordingly, the rotor 40 is positioned in the axial direction. In the present embodiment, it is configured such that the pressing member 35 and the compression coil spring 36 rotate when the rotor 40 rotates, and the compression coil spring 36 makes sliding contact with a sliding contact plate 37 provided on the lid member 23.However, for example, a configuration may be adopted in which the pressing member 35 cannot rotate or is unlikely to rotate, and in which the rotor 40 makes sliding contact with respect to the pressing member 35.

[0023] As in Fig. 5, the inner surface of the rotor receiving portion 15Y in the lower cylindrical portion 15 is a tapered surface 15T extending downward toward the center. A tapered surface 42T, which is tapered, is also formed in the lower edge surface of the rotary screw cylinder 42 in the rotor 40. The rotor 40 is biased downward by the pressing member 35, and thus these tapered surfaces 15T and 42T are in surface contact with each other, with the result that the rotor 40 is centered with respect to the stator 11. The inclination angle of the tapered surface 15T of the lower cylindrical portion 15 is substantially equal to that of the tapered surface 42T of the rotary screw cylinder 42.The inclination angles of these tapered surfaces 15T and 42T are preferably set to such an angle (for example, 15° or less) that the rotary screw cylinder 42 is prevented from being pressed into the depth range of the rotor receiving portion 15Y.

[0024] The upper-end opening edge 42A and the tapered surface 42T of the rotary screw cylinder 42 in the rotor 40 correspond to a “first contact area” in the present invention, and the tapered surface 35T of the pressing member 35 and the tapered surface 15T of the lower cylindrical portion 15 correspond to a “second contact area” in the present invention.

[0025] As in Fig. 1, the linear motion shaft 50 extends in the vertical direction, and a valve element component 55 including the valve element 60 is attached to the lower end portion of a shaft main body 50A having the sliding shaft portion 50B and the external thread portion 50N. More specifically, as shown in Fig. 4, a coupling hole 50D is drilled in the center portion of the lower end surface of the shaft main body 50A in the linear motion shaft 50, and the upper end portion of the valve element component 55 is received in the coupling hole 50D.

[0026] The valve element component 55 is described below. As shown in Fig. 4, the valve element component 55 includes the valve element 60 and a support member 56 fixed to the upper end portion of the valve element 60 by, for example, press-fitting, welding, etc. The valve element 60 includes a valve element main body portion 60A formed in the shape of a truncated cone that tapers downward, a stem portion 60B extending upward from the center of the upper surface of the valve element main body portion 60A, and a flange 60F extending sideways from a position of the valve element main body portion 60A near the upper end. The flange 60F extends sideways further than the linear motion shaft 50.

[0027] The holding member 56 is formed in the shape of a cylinder having a bottom at its lower end and receiving the shaft portion 60B of the valve element 60, and a flange-shaped locking wall 56A is formed at its upper end. In a state where the flange-shaped locking wall 56A is inserted into the coupling hole 50D, a retaining ring 57 is press-fitted into the lower end portion of the coupling hole 50D, and thus, the base end portion of the valve element component 55 is held in the coupling hole 50D. In addition, since the coupling hole 50D is formed to be deeper than the entire length of the holding member 56, the holding member 56 can move linearly inside the coupling hole 50D. Therefore, the valve element 60 fixed to the holding member 56 can move linearly with respect to the linear motion shaft 50.The holding member 56, the coupling hole 50D and the holding ring 57 correspond to a “linear motion coupling mechanism” in the present invention.

[0028] A compression coil spring 58 (which corresponds to a "shaft biasing means," a "valve element biasing means," and a "rotor biasing means" in the present invention) is disposed between the flange 60F of the valve element 60 and the protruding annular plate 25H of the shaft support member 25 in the stator 11. This biases the valve element 60 toward the valve port 18 side. Moreover, the valve element 60 is biased downward with respect to the stator 11, and consequently, the linear motion shaft 50 is also biased downward with respect to the stator 11, and the rotor 40 is also biased downward. The flange 60F of the valve element 60 corresponds to a "pressure receiving portion" in the present invention, and the protruding annular plate 25H of the shaft support member 25 corresponds to an "opposing portion" in the present invention.

[0029] The configuration of the present embodiment has been described above. Next, the operations and effects of the present embodiment will be described. The motor-operated valve 10 of the present embodiment is, for example, incorporated in a body 100 (see Fig. 1). And the rotor 40 rotates by receiving excitation from the stator-side field portion 13, whereby the linear motion shaft 50 having the valve element 60 moves linearly by being screwed into the rotary screw cylinder 42 of the rotor 40, and the opening degree of the valve changes, and accordingly, a flow rate of a coolant flowing between the first flow path R1 and the second flow path R2 changes.

[0030] Here, in the motor-operated valve 10 of the present embodiment, the rotor 40 rotates in a state where the rotor 40 is pressed onto the inner surface (the tapered surface 15T) of the rotor receiving portion 15Y in the stator 11 by the pressing member 35 and the compression coil spring 36, and thus, it is possible to prevent the rotor from rattling in the axial direction, making it possible to reduce vibration noise compared with a conventional case.

[0031] Further, since the tapered surfaces 15T and 42T are respectively formed in the inner surface of the rotor receiving portion 15Y and the lower end surface of the rotary screw cylinder 42 in the rotor 40 and have surface contact with each other, the rotor 40 is centered with respect to the stator 11 and consequently the rotor 40 is also prevented from rattling in the radial direction, which makes it possible to further reduce vibration noise.

[0032] In addition, the tapered surface 35T is also formed in the pressing member 35 and contacts the tapered top-end opening edge 42A of the rotary screw cylinder 42, and accordingly, the rotor 40 is further centered with respect to the stator 11.

[0033] Moreover, in the present embodiment, since the valve element 60 is coupled to the linear motion shaft 50 such that the valve element 60 can move linearly with respect to the linear motion shaft 50, it is possible to absorb an impact resulting from the valve element 60 contacting the opening edge of the valve port 18, and it is also possible to obtain a contact pressure between the valve element 60 and the opening edge of the valve port 18 by the compression coil spring 58.

[0034] Furthermore, regardless of the open state of the valve port 18, the linear motion shaft 50 together with the valve element 60 is biased downward with respect to the rotor 40 by the compression coil spring 58, and thus, it is possible to reduce vibration noise caused by rattling between the linear motion shaft 50 and the rotor 40. In addition, the linear motion shaft 50 is biased downward and consequently the rotor 40 is also biased downward, which makes it possible to further improve the pressing of the rotor 40 against the inner surface of the rotor receiving portion 15Y.

[0035] Furthermore, in the present embodiment, the compression coil spring 58 that biases the valve element 60 is used for both biasing the rotor 40 and biasing the linear motion shaft 50, and thereby reducing the number of components. [Other embodiments]

[0036] The present invention is not limited to the embodiment described above, and for example, embodiments described below may also be included in the technical scope of the present invention, and further, various variations other than those described below may be implemented without departing from the gist thereof. (1) Although in the above-described embodiment, both the inner surface of the rotor receiving portion 15Y and the lower end surface of the rotary screw cylinder 42 in the rotor 40 are tapered, only one of them may be tapered as shown in Fig. 6 or Fig. 7 shown. (2) Although in the above-described embodiment, the tapered surface 15T of the rotor receiving portion 15Y and the tapered surface 42T of the rotary screw cylinder 42 in the rotor 40 are inclined downward toward the central portion, they may be inclined upward toward the central portion as shown in Fig. 8 shown. (3) Although in the above-described embodiment, the inner surface of the rotor receiving portion 15Y and the lower end surface of the rotary screw cylinder 42 in the rotor 40 are in surface contact with each other, a protrusion, a roller, or the like may be provided in one of the surfaces so that they contact each other either at points or lines. In such cases, the number of points or lines where the rotor receiving portion 15Y contacts the rotary screw cylinder 42 is preferably three or more. (4) Although in the above-described embodiment, the tapered surface 35T is formed in the pressing member 35, the tapered surface 35T may not be shaped or the shape of the pressing member 35 may be flat. (5) Although in the above-described embodiment, the "valve element biasing means" also serves as the "shaft biasing means" in the present invention, they may be provided separately. As such an example, for example, a configuration can be cited in which a compression coil spring serving as the "shaft biasing means" in the present invention is inserted through the male thread portion 50N of the linear motion shaft 50 and accommodated in a compressed state between the lower opening edge of the female thread portion 42N of the rotary screw cylinder 42 and the stepped surface between the male thread portion 50N and the slide shaft portion 50B in the linear motion shaft 50. (6) The “rotor biasing means” in the present invention may be configured with only the compression coil spring 58 or may be configured with only the compression coil spring 36. (7) Although in the above-described embodiment, the “rotor biasing means” is the compression coil springs 36 and 58, another elastic member (such as a disc spring or rubber) may be used, and for example, a configuration may be adopted in which a weight is attached to the rotor 40 so that the rotor 40 is biased by the weight thereof, or a configuration may be adopted in which magnets are attached to the rotor 40 and the cover member 23 of the stator 11 so that they repel each other and thereby bias the rotor 40 by their repulsive force. (8) Similarly, although in the above-described embodiment, the “valve element biasing means” and the “shaft biasing means” in the present invention are the compression coil spring 58, another elastic member (such as a disc spring or rubber) may be used, and for example, a configuration may be adopted in which a weight is attached to the valve element 60 so that the linear motion shaft 50 is biased by the weight thereof, or a configuration may be adopted in which magnets are attached to the valve element 60 and the shaft support member 25 of the stator 11 so that they repel each other and thereby bias the valve element 60 by their repulsive force. DESCRIPTION OF REFERENCE SYMBOLS 10 motor-operated valve 11 Stator 15T tapered surface (stator-side sliding contact area) 15Y rotor mounting area 18 Valve connection 20 Stepper motor (motor) 25 Shaft support element 25D shaft receiving opening 30 leadership 31 Spiral guide 32 stop ring 35 Press element (intermediate element) 35T tapered surface (stator-side sliding contact area) 36 Compression coil spring (rotor preloading device) 40 rotor 42 rotary screw cylinders 42A upper-end opening edge (rotor-side sliding contact area) 50 linear motion shaft 55 Valve element component 58 Compression coil spring (valve preloading means, stem preloading means and rotor preloading means) 60 valve element

Claims

[1] Motor-operated valve (10) comprising: an engine (20); a base portion (15) formed at one end of a stator (11) of the motor (20); a linear motion shaft (50) screwed into a rotor (40) of the motor (20) and supported by the base portion (15) such that the linear motion shaft (50) can move linearly and cannot rotate; a valve port (18) formed in the base portion (15); a valve element (60) arranged at one end of the linear motion shaft (50) and opening and closing the valve port (18); an intermediate member (35) arranged between the rotor (40) and the stator (11); a first contact area (42A, 42T) on the rotor (40) and a second contact area (15T, 35T) on the stator (11) and on the intermediate member (35), wherein the first contact area (42A, 42T) is formed on a rotary screw cylinder (42) of the rotor (40) and the second contact area (15T, 35T) is formed on the intermediate member (35) and on the base area (15), and wherein the first contact area (42A, 42T) and the second contact area (15T, 35T) contact each other in a rotational axis direction of the rotor (40); and a rotor biasing means (36, 58) which biases the rotor (40) in the rotation axis direction such that the first contact portion (42A, 42T) and the second contact portion (35T) are pressed against each other. [2] Motor-operated valve (10) according to claim 1, wherein the first contact region (42A, 42T) is formed in both end regions of the rotor (40), the second contact portion (35T) is formed at two positions that sandwich the rotor (40) in the rotation axis direction, and the second contact portion (35T) is formed at least one of the two positions in the intermediate member (35) that can move linearly with respect to a main body (12, 13, 23) of the stator (11), and an elastic member (36) serving as the rotor biasing means is formed between the intermediate member (35) and the main body (12, 13, 23) of the stator (11). [3] Motor-operated valve (10) according to claim 2, comprising: a guide shaft (30) attached to the main body (12, 13, 23) of the stator (11) and extending coaxially with the linear motion shaft (50); a spiral guide (31) formed on an outer surface of the guide shaft (30); and a stop ring (32) attached to the guide shaft (30) and moving from an upper end to a lower end of the spiral guide (31) according to rotation of the rotor (40) so as to regulate a rotation amount of the rotor (40), wherein the intermediate element (35) is held by the guide shaft (30). [4] The motor-operated valve (10) according to any one of claims 1 to 3, wherein a tapered surface (15T, 35T, 42T) is formed in one or both of the first contact portion (42A, 42T) and the second contact portion (15T, 35T) to centrally align the rotor (40) with respect to the stator (11). [5] Motor-operated valve (10) according to one of claims 1 to 4, comprising: a shaft biasing means (58) biasing the linear motion shaft (50) in one of the linear motion directions with respect to the rotor (40). [6] Motor-operated valve (10) according to one of claims 1 to 5, wherein the valve port (18) is arranged opposite the valve element (60) on a side opposite to the linear movement shaft (50), and the motor-operated valve (10) contains: a linear motion coupling mechanism that couples the valve element (60) to an end portion of the linear motion shaft (50) such that the valve element (60) can move linearly and cannot separate; and a valve element biasing means (58) biasing the valve element (60) toward the valve port (18) with respect to the linear motion shaft (50). [7] The motor-operated valve (10) of claim 6, wherein the valve element biasing means (58) also serves as the rotor biasing means. [8] Motor-operated valve (10) according to claim 6 or 7, comprising: a pressure receiving portion (60F) formed in the valve element (60) and extending further sideways than the linear motion shaft (50); a shaft support member (25) attached to an upper end portion of a valve element linear movement space (15X) in the base portion (15); an opposing portion (25H) formed on the shaft support member (25) and facing the pressure receiving portion (60F) from a side opposite to the valve port (18); and a compression coil spring (58) located between the pressure receiving portion (60F) and the opposing portion (25H) and biasing the valve element (60) toward the valve port (18) side and serving as the valve element biasing means (58).

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