阅读说明：本技术 电动阀以及冷冻循环系统 (Electric valve and refrigeration cycle system ) 是由 中野诚一 于 2019-06-17 设计创作，主要内容包括：本发明提供电动阀以及冷冻循环系统。在电动阀的阀架部(2)中,使垫圈(21)始终可靠地抵接于转子轴(1)的凸缘部(12),确保稳定的工作性。在转子轴(1)中,在凸台部(11)与凸缘部(12)之间的凹角部形成作为“后退部”的圆环状的水平V槽(13)。将凸台部(11)插通于垫圈(21)的插通孔(21a),将垫圈(21)配置在导向管(22)的顶面部(22b)与凸缘部(12)之间。由此,相对于转子轴(1)连结阀架部(2)。“后退部”也可以形成于垫圈(21)的插通孔(21a)的下侧开口部的凸角部。(The invention provides an electric valve and a refrigeration cycle system. In a valve frame part (2) of an electric valve, a gasket (21) is always reliably contacted with a flange part (12) of a rotor shaft (1), and stable operability is ensured. In the rotor shaft (1), an annular horizontal V-groove (13) is formed as a "receding section" in a recessed corner portion between a boss portion (11) and a flange portion (12). The boss part (11) is inserted into an insertion hole (21a) of the washer (21), and the washer (21) is disposed between the top surface part (22b) of the guide pipe (22) and the flange part (12). Thus, the valve frame part (2) is connected to the rotor shaft (1). The "receding portion" may be formed at a convex portion of the lower opening of the insertion hole (21a) of the gasket (21).)

1. An electrically operated valve in which a valve port is opened and closed by a valve member interlocked with an operating shaft of a motor part, wherein a flange part is formed on the outer periphery of an end part of the operating shaft, and a valve frame part holding the valve member and connected with the flange part of the operating shaft is provided,

the above-mentioned electric valve is characterized in that,

the valve frame portion is configured such that a washer having an insertion hole into which the operating shaft is inserted is disposed between an annular top surface portion formed at an end portion of a cylindrical guide pipe and the flange portion,

a receding portion receding from the other is provided on at least one of a recessed corner portion formed by a side surface of the operating shaft inserted into the insertion hole and a contact surface of the flange portion with respect to the washer, and a protruding corner portion formed by an inner peripheral surface of the insertion hole and a contact surface of the washer with respect to the flange portion.

2. Electrically operated valve according to claim 1,

the retreating section is formed of a recess provided in the concave portion of the operating shaft.

3. Electrically operated valve according to claim 1,

the receding portion is formed of a concave portion provided in the convex portion of the gasket.

4. Electrically operated valve according to claim 3,

the recessed portion is a stepped portion, a chamfered portion, or an arc surface portion.

5. Electrically operated valve according to claim 4,

the height of the recessed portion is larger than the radius of the arc portion of the recessed portion in the operating shaft.

6. Electrically operated valve according to claim 5,

the concave portions are formed on both surfaces of the gasket.

7. A refrigeration cycle system comprising a compressor, a condenser, an expansion valve, and an evaporator,

an electrically operated valve as claimed in any one of claims 1 to 6 is used as the expansion valve.

Technical Field

The present invention relates to an electrically operated valve and a refrigeration cycle system used in a refrigeration cycle or the like.

Background

Conventionally, as such an electrically operated valve, there is an electrically operated valve in which a valve port is opened and closed by a valve member connected to a working shaft of a motor unit. Such an electrically operated valve is disclosed in, for example, japanese patent application laid-open No. 2017-161052 (patent document 1). In the motor-operated valve of patent document 1, a flange portion of the operating shaft is provided in a valve frame portion so as to connect the valve frame portion (valve guide) holding the valve member and the operating shaft (valve shaft), and a washer is interposed between an end portion of the valve frame portion and the flange portion. In addition, the washer is provided for rotation of the operating shaft and thereby free rotation of the operating shaft and the valve frame relative to each other.

Disclosure of Invention

Problems to be solved by the invention

In the technique of patent document 1 described above, as shown in fig. 15, a flange portion 82 of a boss portion 81 formed at an end portion of the rotor shaft 8 as the operating shaft is provided in a guide pipe 92 of the valve housing portion, and a washer 91 is disposed so as to mesh between a top surface portion 92a of an upper end of the guide pipe 92 and the flange portion 82. However, in terms of machining accuracy in machining the rotor shaft 8, the arc portion 8R may be generated at a concave angle between the boss portion 81 and the flange portion 82 of the rotor shaft 8. In this case, when a lateral misalignment occurs between the rotor shaft 8 and the guide pipe 92 (valve frame portion), the washer 91 jumps up the arcuate portion 8R, and the guide pipe 92 (and the valve body) tilts with respect to the rotor shaft 8, which may deteriorate workability.

The subject of the invention is to ensure stable operability by causing a gasket of a valve frame part to always and reliably abut against a flange part of an operating shaft in an electric valve provided with the valve frame part which holds a valve part and is connected with the flange part of the operating shaft.

Means for solving the problems

The electric valve of the proposal 1 is an electric valve which opens and closes a valve port through a valve component interlocked with a working shaft of a motor part, a flange portion is formed on an outer periphery of an end portion of the operating shaft, and a valve frame portion that holds the valve member and is coupled to the flange portion of the operating shaft is provided, wherein the valve frame portion is configured, a washer is arranged between an annular top surface part formed at the end part of the cylindrical guide pipe and the flange part, the washer has an insertion hole into which the operating shaft is inserted, and at least one of the recessed corner portion and the projecting corner portion is provided with a receding portion receding from the other, the recessed corner portion is formed by a side surface of the operating shaft inserted into the insertion hole and an abutting surface of the flange portion against the washer, the convex portion is formed by an inner peripheral surface of the insertion hole in the washer and an abutment surface portion with respect to the flange portion.

The electrically operated valve according to claim 2 is characterized in that the receding portion is formed of a recessed portion provided in the recessed portion of the operating shaft, as shown in claim 1.

The electrically operated valve according to claim 3 is characterized in that the receding portion is formed of a recessed portion provided in the flange portion of the gasket, in the electrically operated valve according to claim 1.

The electrically operated valve according to claim 4 is characterized in that the recessed portion is a stepped portion, a chamfered portion, or an arc surface portion.

The electrically operated valve according to claim 5, wherein the height of the recessed portion is larger than the radius of the circular arc portion of the recessed portion in the operating shaft.

The electrically operated valve according to claim 6 is characterized in that the recess is formed on both surfaces of the gasket, in the electrically operated valve according to claim 5.

The refrigeration cycle system according to claim 7 is a refrigeration cycle system including a compressor, a condenser, an expansion valve, and an evaporator, and is characterized in that the electric valve according to any one of claims 1 to 6 is used as the expansion valve.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the motor-operated valve of claims 1 to 6, since the receding portion is provided on at least one of the recessed portion in the operating shaft and the raised portion in the washer, the recessed portion and the raised portion do not interfere with each other. Therefore, even if a lateral offset occurs between the operating shaft and the valve frame portion, the valve frame portion and the valve member do not tilt with respect to the operating shaft, and the gasket of the valve frame portion can be reliably brought into contact with the flange portion of the operating shaft at all times, so that stable operability can be ensured.

According to the refrigeration cycle system of embodiment 7, the same effects as those of embodiments 1 to 6 can be obtained.

Drawings

Fig. 1 is a longitudinal sectional view of an electric valve according to a first embodiment of the present invention.

Fig. 2 is an enlarged view of a main portion of the electric valve of the first embodiment.

Fig. 3 is a partially enlarged view of a portion shown by a dotted circle of fig. 2.

Fig. 4 is an enlarged sectional view of a principal part illustrating a concave portion of the rotor shaft and a convex portion of the washer in the first embodiment.

Fig. 5 is a diagram showing a modification 1 of the "retreating section" in the first embodiment.

Fig. 6 is a diagram showing a modification 2 of the "retreating section" in the first embodiment.

Fig. 7 is a diagram showing a modification 3 of the "retreating section" in the first embodiment.

Fig. 8 is an enlarged view of a main portion of an electrically operated valve according to a second embodiment of the present invention.

Fig. 9 is a partially enlarged view of a portion shown by a dotted circle of fig. 8.

Fig. 10(a) to (B) are views showing a modification 4 of the "receding portion" in the second embodiment.

Fig. 11(a) to (B) are views showing a modification 5 of the "receding portion" in the second embodiment.

Fig. 12(a) to (B) are views showing a modification 6 of the "receding portion" in the second embodiment.

Fig. 13(a) to (C) are views showing modifications of the gasket in the embodiment.

Fig. 14 is a diagram showing a refrigeration cycle system according to an embodiment.

Fig. 15 is a diagram illustrating a problem in the conventional motor-operated valve.

In the figure:

1-rotor shaft (operating shaft), 1Q-circular arc portion, 11-boss portion, 12-flange portion, 12 a-upper abutment surface, 13-horizontal V groove (receding portion), 14-vertical V groove (receding portion), 15-horizontal square groove (receding portion), 16-vertical square groove (receding portion), 2-valve frame portion, 21-gasket, 21 a-insertion hole, 21 b-lower abutment surface, 21 c-step portion (receding portion), 21 d-chamfer portion (receding portion), 21 e-circular arc portion (receding portion), 22-guide tube, 22 a-insertion hole, 22 b-top surface portion, 3-needle valve (valve member), 10-stepping motor (motor portion), 10 a-magnetic rotor, 10 b-stator coil, 20-valve housing, 20R-valve chamber, 30-sealed housing, 40-support member, 40 a-internal thread portion, 40 b-guide hole, 1 a-threaded portion, 50-first joint pipe, 60-second joint pipe, 70-valve seat component, 70 a-valve port, A-concave angle part, B-convex angle part, 100-electric valve, 200-outdoor heat exchanger, 300-indoor heat exchanger, 400-flow path switching valve, 500-compressor.

Detailed Description

Embodiments of an electric valve and a refrigeration cycle system according to the present invention will be described below with reference to the drawings. Fig. 1 is a longitudinal sectional view of an electric valve according to a first embodiment, fig. 2 is an enlarged view of a main portion of the electric valve according to the first embodiment, fig. 3 is a partially enlarged view of a portion shown by a dotted circle in fig. 2, and fig. 4 is an enlarged sectional view of a main portion illustrating a concave portion of a rotor shaft and a convex portion of a washer according to the first embodiment. Note that the concept of "top and bottom" in the following description corresponds to the top and bottom in the drawing of fig. 1.

The motor-operated valve 100 includes a rotor shaft 1, a valve frame 2, a needle valve 3 as a "valve member", a stepping motor 10 as a "motor portion", a valve housing 20, a sealed housing 30 made of a nonmagnetic material, and a support member 40. The valve housing 20 and the hermetic case 30 are hermetically fastened, and the stepping motor 10 is configured inside and outside the hermetic case 30. The stepping motor 10 includes a magnetic rotor 10a rotatably disposed inside the sealed casing 30, a stator coil 10b disposed on the outer periphery of the sealed casing 30 so as to face the magnetic rotor 10a, and other yokes and exterior members, not shown. The rotor shaft 1 is attached to the center of the magnetic rotor 10a via a bushing, and a male screw portion 1a is formed on the outer periphery of the rotor shaft 1 on the side of the support member 40. A valve frame portion 2, which will be described later, is attached to the lower end of the rotor shaft 1. A rotation restricting mechanism 30a is provided at an upper portion in the sealed case 30, and the rotation restricting mechanism 30a restricts rotation of the magnetic rotor 10a in cooperation with the projection of the magnetic rotor 10 a.

The valve housing 20 is formed of stainless steel or the like into a substantially cylindrical shape, and has a valve chamber 20R inside thereof. A first joint pipe 50 that communicates with the valve chamber 20R is connected to one side of the outer periphery of the valve housing 20, and a second joint pipe 60 is connected to a cylindrical portion extending downward from the lower end. Further, a valve seat member 70 is fitted to the valve chamber 20R side of the second joint pipe 60. The inside of the valve seat member 70 is a valve port 70a, and the second joint pipe 60 is communicated with the valve chamber 20R through the valve port 70 a.

The support member 40 is made of, for example, synthetic resin, is formed into a substantially cylindrical shape, and is fixed to the upper end portion of the valve housing 20 at the outer periphery thereof by welding or the like via a stainless steel flange portion 41 integrally provided by insert molding. A female screw portion 40a coaxial with the axis X of the rotor shaft 1 and a screw hole thereof are formed at the center of the support member 40, and a cylindrical guide hole 40b having a larger diameter than the screw hole of the female screw portion 40a is formed. The valve holder 2 and the needle valve 3 are provided in the support member 40 and the valve chamber 20R, and the valve holder 2 is attached to the lower end of the rotor shaft 1.

The valve frame portion 2 includes: an annular washer (thrust washer) 21 having an insertion hole 21a, a guide tube 22 formed of a cylindrical member, a spring seat 23, and a coil spring 24. The guide tube 22 includes an annular top surface portion 22b having an insertion hole 22a by bending an upper end portion inward. On the other hand, the rotor shaft 1 has a boss portion 11 at an end portion on a lower end side than the male screw portion 1a, and a flange portion 12 is integrally formed on the boss portion 11. A washer 21 is attached to the boss portion 11 so as to fit into the insertion hole 21 a. Further, the washer 21, the boss portion 11, and the flange portion 12 are accommodated in the guide pipe 22 by fitting the rotor shaft 1 into the insertion hole 22 a. Thereby, the washer 21 is disposed between the top surface portion 22b of the guide pipe 22 and the flange portion 12. A spring seat 23 is provided in the guide tube 22 so as to be movable in the direction of the axis X, and the needle valve 3 is fastened to the lower end of the guide tube 22 in a state where the spring seat 23 and the coil spring 24 are housed.

As described above, the valve frame portion 2 having the needle valve 3 is fitted in the guide hole 40b of the support member 40 and is arranged slidably in the axis X direction. The male screw portion 1a of the rotor shaft 1 is screwed into the female screw portion 40a of the support member 40, the upper end portion of the valve holder portion 2 is engaged and held with the lower end portion of the rotor shaft 1 in the guide hole 40b of the support member 40, and the valve holder portion 2 and the needle valve 3 are supported in a state suspended rotatably by the rotor shaft 1.

According to the above configuration, the magnetic rotor 10a and the rotor shaft 1 are rotated by the driving of the stepping motor 10, and the rotor shaft 1 is moved in the axis X direction by the screw feeding mechanism of the male screw portion 1a of the rotor shaft 1 and the female screw 40a of the support member 40. The needle valve 3 moves in the direction of the axis X to approach or separate from the valve seat member 70. Thus, the opening/closing valve port 70a controls the flow rate of the refrigerant flowing from the first joint pipe 50 to the second joint pipe 60 or from the second joint pipe 60 to the first joint pipe 50.

Fig. 4 shows a state in which the washer 21 is assembled to the rotor shaft 1. As shown in the drawing, in the rotor shaft 1, the upper abutment surface 12a of the flange portion 12 intersects with an extension surface of the outer peripheral surface of the boss portion 11, and the outer peripheral surface of the boss portion 11 is perpendicular to the upper abutment surface 12a to form a recessed corner portion a (a portion surrounded by a dashed-dotted line). In the gasket 21, a convex portion B (a portion surrounded by a chain line) is formed at a right angle between the inner peripheral surface of the insertion hole 21a and the lower contact surface 21B. Note that the reentrant corner portion a and the reentrant corner portion B are the same in a modification and a second embodiment described later, and fig. 4 is also used for the description of the modification and the second embodiment.

In the first embodiment, an annular horizontal V groove 13 as a "receding portion" having a smaller diameter than the outer diameter of the boss portion 11 is formed between the boss portion 11 and the flange portion 12 of the rotor shaft 1. Fig. 3 shows only one-sided cross-sectional shape, but the horizontal V-groove 13 has an annular structure formed around the axis X. That is, the horizontal V groove 13 is provided in the recessed corner portion a of the rotor shaft 1 so as to recede from the convex corner portion B on the washer 21 side toward the center side. As a result, as shown in fig. 3, in a state where the washer 21 is assembled to the rotor shaft 1, the lower contact surface 21b of the washer 21 reliably contacts the upper contact surface 12a of the flange portion 12.

As described above, the annular horizontal V groove 13 as the "receding portion" of the rotor shaft 1 allows the lower contact surface 21b on the washer 21 side to reliably contact the upper contact surface 12a of the flange portion 12 without interfering with the recessed corner portion a. Even if a lateral offset occurs between the rotor shaft 1 and the valve holder portion 2, the valve holder portion 2 (and the needle valve 3) does not tilt relative to the rotor shaft 1, and the washer 21 of the valve holder portion 2 can be reliably brought into contact with the flange portion 12 of the rotor shaft 1 at all times, so that stable operability can be ensured.

Fig. 5 to 7 are views showing modifications 1 to 3 of the "receding portion" in the first embodiment. In the following modifications and second embodiment, the same elements as those of the first embodiment are denoted by the same reference numerals as those of fig. 1 to 4, and overlapping descriptions are omitted as appropriate. In the figure, only one side cross-sectional shape is shown, but the vertical V-groove 14, the horizontal square groove 15, and the vertical square groove 16 described below have an annular structure formed around the entire circumference of the axis X.

Modification 1 of fig. 5 is an example in which an annular vertical V groove 14 as a "receding portion" is formed so that the outer peripheral surface of the boss portion 11 of the rotor shaft 1 extends in the axial direction. That is, the vertical V-groove 14 is provided at the recessed portion a (see fig. 4) of the rotor shaft 1 so as to recede in the axial direction from the protruding portion B (see fig. 4) on the washer 21 side.

In modification 2 of fig. 6, an annular horizontal square groove 15 as a "receding portion" is formed so that the upper contact surface 12a of the flange portion 12 of the rotor shaft 1 extends toward the center. That is, the horizontal square groove 15 is provided at the recessed portion a (see fig. 4) of the rotor shaft 1 so as to recede from the raised portion B (see fig. 4) on the washer 21 side toward the center side.

Modification 3 of fig. 7 is an example in which an annular vertical square groove 16 as a "receding portion" is formed so that the outer peripheral surface of the boss portion 11 of the rotor shaft 1 extends in the axial direction. That is, the vertical square groove 16 is provided at the recessed portion a (see fig. 4) of the rotor shaft 1 so as to recede in the axial direction from the projecting portion B (see fig. 4) on the washer 21 side.

Even in the above modifications 1 to 3, since the lower abutment surface 21b on the washer 21 side can be reliably brought into abutment with the upper abutment surface 12a of the flange portion 12 by the vertical V groove 14, the horizontal square groove 15, and the vertical square groove 16, the position of the valve frame 2 (and the needle valve 3) with respect to the rotor shaft 1 can be accurately maintained, and stable operability can be obtained.

Fig. 8 is an enlarged view of a main portion of an electrically operated valve according to a second embodiment, and fig. 9 is a partial enlarged view of a portion indicated by a dashed-dotted circle in fig. 8. In the second embodiment, an annular step portion 21c as a "receding portion" is formed around the lower opening of the insertion hole 21a of the gasket 21. That is, the stepped portion 21c is formed by surfaces perpendicular to the inner peripheral surface of the insertion hole 21a and the lower contact surface 21B, and the stepped portion 21c is provided at the convex portion B (see fig. 4) of the washer 21 so as to recede outward from the concave portion a (see fig. 4) on the rotor shaft 1 side. As a result, as shown in fig. 9, even if the arc portion 1Q is formed at the recessed corner portion a of the rotor shaft 1, the lower contact surface 21b on the washer 21 side can be reliably brought into contact with the upper contact surface 12a of the flange portion 12. The height H1 of the stepped portion 21c and the radius R1 of the arc portion 1Q are H1 > R1. Therefore, the position of the valve holder 2 (and the needle valve 3) with respect to the rotor shaft 1 can be accurately maintained, and stable operability can be obtained.

Fig. 10(a) to 12(B) are views showing modifications 4 to 6 of the "receding portion" in the second embodiment, in which the view (a) is a partially enlarged view of a portion corresponding to a circle of a chain line in fig. 8, and the view (B) is a whole cross-sectional view of the gasket 21.

Modification 4 of fig. 10(a) to (B) is an example in which an annular chamfered portion 21d as a "receding portion" is formed around the lower opening of the insertion hole 21a of the gasket 21. That is, the chamfered portion 21d is a surface intersecting the inner peripheral surface of the insertion hole 21a and the lower abutment surface 21B, respectively, and the chamfered portion 21d is provided at the convex portion B (see fig. 4) of the washer 21 so as to recede outward from the concave portion a (see fig. 4) on the rotor shaft 1 side. Further, the height H2 of the chamfered portion 21d and the radius R1 of the arc portion 1Q are H2 > R1.

Modification 5 of fig. 11(a) to (B) is an example in which an annular arcuate surface portion 21e as a "receding portion" is formed around the lower opening portion of the insertion hole 21a of the washer 21, and the arcuate surface portion 21e is provided at the convex portion B (see fig. 4) of the washer 21 so as to recede outward from the concave portion a (see fig. 4) on the rotor shaft 1 side. The radius R2, i.e., the height of the arc portion 21e and the radius R1 of the arc portion 1Q are R2 > R1.

Even in the above modifications 4 and 5, the chamfered portion 21d and the arc surface portion 21e can reliably bring the lower contact surface 21b on the washer 21 side into contact with the upper contact surface 12a of the flange portion 12, and the position of the valve holder 2 (and the needle valve 3) with respect to the rotor shaft 1 can be accurately maintained, thereby obtaining stable operability.

Modification 6 of fig. 12(a) to (B) is an example in which annular step portions 21c similar to those of the second embodiment are formed around both the upper and lower openings of the insertion hole 21a of the thrust washer 21, and the operational effect of the lower step portion 21c is similar to that of the second embodiment. In the case of modification 6, when the washer 21 is assembled to the rotor shaft 1, it is not necessary to consider the front and rear surfaces of the washer 21, and the assembly work is easy. In addition, the configuration in which the "receding portions" are provided on both surfaces of the gasket 21 in this manner can be similarly applied to the modifications 1 to 5.

The shape of each gasket 21 of the first and second embodiments may be an annular (ring-shaped) gasket 21 as shown in fig. 13(a), a C-shaped gasket 21 having a notch 21d in a part of the annular shape as shown in fig. 13(B), or a U-shaped gasket 21 having a notch 21d in a part of the annular shape as shown in fig. 13(C), as viewed from above in the gasket portion of each drawing. The washer 21 having the C-shape or the U-shape can be assembled to the working shaft from the lateral direction, and has an effect of excellent assembling property. The C-shaped or U-shaped washer 21 also has an insertion hole 21a for inserting the operating shaft, similarly to the annular (ring-shaped) washer 21.

Fig. 14 is a diagram showing a refrigeration cycle system according to an embodiment. In the figure, reference numeral 100 denotes an electrically operated valve constituting an expansion valve according to each embodiment of the present invention, reference numeral 200 denotes an outdoor heat exchanger mounted in an outdoor unit, reference numeral 300 denotes an indoor heat exchanger mounted in an indoor unit, reference numeral 400 denotes a flow path switching valve constituting a four-way valve, and reference numeral 500 denotes a compressor. The motor-operated valve 100, the outdoor heat exchanger 200, the indoor heat exchanger 300, the flow path switching valve 400, and the compressor 500 are connected by pipes as shown in the figure, and constitute a heat pump type refrigeration cycle. The accumulator, the pressure sensor, the temperature sensor, and the like are not shown.

The flow path of the refrigeration cycle is switched by the flow path switching valve 400 to two flow paths, i.e., a flow path during the cooling operation and a flow path during the heating operation. During the cooling operation, as shown by solid arrows in the figure, the refrigerant compressed by the compressor 500 flows from the flow path switching valve 400 into the outdoor heat exchanger 200, the outdoor heat exchanger 200 functions as a condenser, the liquid refrigerant flowing out of the outdoor heat exchanger 200 flows into the indoor heat exchanger 300 via the motor-operated valve 100, and the indoor heat exchanger 300 functions as an evaporator.

On the other hand, during the heating operation, as indicated by the broken-line arrows in the figure, the refrigerant compressed by the compressor 500 circulates from the flow path switching valve 400 to the indoor heat exchanger 300, the motor-operated valve 100, the outdoor heat exchanger 200, the flow path switching valve 400, and the compressor 500 in this order, and the indoor heat exchanger 300 functions as a condenser and the outdoor heat exchanger 200 functions as an evaporator. The motor-operated valve 100 depressurizes and expands the liquid refrigerant flowing from the outdoor heat exchanger 200 during the cooling operation or the liquid refrigerant flowing from the indoor heat exchanger 300 during the heating operation, and controls the flow rate of the refrigerant.

The receding portion (fig. 1 to 4) and the modification 1 (fig. 5) of the receding portion in the first embodiment are V-grooves in the horizontal and vertical directions, but may be arc-shaped grooves. Further, although the modified examples 2 and 3 (fig. 6 and 7) of the receding portion of the first embodiment are horizontal and vertical square grooves, the corner portion of the recessed corner portion on the back surface of the square groove may be rounded. The stepped portion 21c of the receding portion (fig. 9) and the modified example 6 of the receding portion (fig. 12(a) to (B)) of the second embodiment has a right angle in the drawing, but may be a stepped portion having a circular arc at the corner of the concave portion and the convex portion of the step. In addition, although the chamfer portion 21d of the modification 4 (fig. 10(a) to (B)) of the receding portion of the second embodiment is an angle between the chamfer start portion and the chamfer end portion in the drawing, it may be a chamfered portion with a circular arc in which the angle is circular arc.

In the above description, the "rotor shaft 1 has the boss portion 11 at the end portion on the lower end side than the male screw portion 1a, and the flange portion 12 is integrally formed on the boss portion 11. However, the flange portion is not limited to being formed integrally with the rotor shaft, and may be formed separately from the rotor shaft (operating shaft). Therefore, the flange portion may be formed by fastening a separate member (flange member) to the outer periphery of the end portion of the operating shaft.

While the embodiments of the present invention have been described in detail with reference to the drawings, the specific configurations are not limited to these embodiments, and design changes and the like that do not depart from the scope of the present invention are also included in the present invention.