JP2000032699A - Motor for valve drive, with increased sealing performance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a motor which eliminates the possibility that a fluid such as a gas or the like leaks. SOLUTION: A synthetic resin 8 is integrally molded with a stator 3, in such a way that the stator 3 is airtight. A lid 11 is attached airtightly to the stator 3 via an O-ring 12. In addition, the stator 3 is integrated with a yoke 4 and yoke 4 by a synthetic resin 5. Coils 7, 7 are wound on their outer circumference.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor used for a valve which is interposed in a fluid pipe and is closed by a valve element provided on a rotating shaft.

[0002]

2. Description of the Related Art Conventionally, a stepping motor has been known as a motor used for a gas shutoff valve. This stepping motor includes a rotor having a shaft, a stator in which a coil is wound around an outer periphery of a yoke and covers the rotor via a gap, a case for housing the stator, a rotor for closing an opening of the case, and And a lid to which a bearing that rotatably supports the shaft is attached.
A valve attached to a portion of the rotor shaft protruding outward from the lid closes the gas supply line when an earthquake is detected.

[0003]

However, in such a conventional stepping motor, a small amount of gas enters the stepping motor from the gas supply line through the bearing of the lid, and the gas is supplied to the coil. May leak to the outside through between the windings, between the yokes, or between the stator and the lid. SUMMARY OF THE INVENTION It is an object of the present invention to provide a valve driving motor having an improved hermetic seal that does not leak a fluid such as a gas.

[0004]

According to a first aspect of the present invention, there is provided a valve driving motor having improved sealing performance according to the present invention, wherein the motor is provided in a fluid pipe and has a rotating shaft. A motor used for a valve that closes the fluid conduit with a provided valve element, the rotor including the shaft,
A stator in which a coil is wound around the outer periphery of the yoke and covers the rotor via a gap, a case for housing the stator, and a bearing for closing an opening of the stator and rotatably supporting the shaft of the rotor And a synthetic resin is integrally molded with the stator so that the stator has sealing properties, and the lid is attached to the stator via a sealing member. It is characterized by having. Further, the valve driving motor with improved sealing according to the present invention according to claim 2 is the invention according to claim 1,
The stator is characterized in that the yoke is integrated with a synthetic resin, and a coil is wound around the outer periphery of the yoke.

According to the first or second aspect of the present invention, a synthetic resin is integrally formed on the stator so that the stator has a sealing property, and a lid is attached to the stator via a sealing member. Therefore, fluid such as gas which has entered the motor from the fluid line through the bearing of the lid does not leak outside between the windings of the coil, between the yokes, or between the stator and the lid. Further, conventionally, there was a possibility that the coil winding was broken due to a lightning surge due to a narrow gap between the case and the coil where only air was interposed. If the outer periphery of the coil is covered with the synthetic resin, the synthetic resin is interposed between the coil and the inner peripheral surface of the case, so that the insulation performance is improved. Therefore, damage to the motor due to a lightning surge is prevented. According to the second aspect of the present invention, since the stator is formed by integrating the yoke with a synthetic resin and winding a coil around the outer periphery, positioning and fixing between the yokes can be performed accurately and easily.

[0006]

FIG. 1 is a longitudinal sectional view showing an embodiment of a gas shut-off valve as an example of a valve according to the present invention.
In the figure, reference numeral M denotes a stepping motor (motor) according to the present invention.
Is provided at the center with a rotor 1 alternately magnetized in the circumferential direction on the outer peripheral surface 1A. A shaft 2 is fixed to the center of the rotor 1. A stator 3 is arranged outside the rotor 1 with a slight space therebetween. The stator 3 includes a yoke 4 provided in the axial direction of the rotor 1,
A synthetic bobbin 4 is formed integrally with a synthetic resin 5 by injection molding to form a cylindrical bobbin 6, and coils 7 and 7 are wound around the outer circumferences of the yokes 4 and 4 of the bobbin 6, respectively. Inner peripheral surfaces 4A, 4 of the yokes 4, 4
A has a plurality of pole teeth arranged at equal intervals in the circumferential direction. The rotor 1 is rotated by energizing the coils 7 to alternately excite these pole teeth to different poles.

The stator 3 formed on the cylindrical bobbin 6
Is formed by integrally molding a synthetic resin 8 by injection molding to form a bottomed cylindrical shape. The synthetic resin 8 is formed so as to cover the inner periphery of the bobbin 6 without a gap, thereby preventing gas from leaking between the yokes 4 and 4. The synthetic resin 8 is also formed on the outer periphery of the bobbin 6, and the outer periphery of the coils 7, 7 is covered with the synthetic resin 8, but the outer end surfaces of the yokes 4, 4 are exposed.

A fitting recess 9A is formed in the center of the stator 3 inside the bottomed portion 9 made of the synthetic resin 8, and the fitting recess 9A rotatably supports one end of the shaft 2 of the rotor 1. are doing. On the other hand, on the opening side of the stator 3, a lid 11 for closing the opening is hermetically attached via an O-ring (sealing member) 12. That is, a ring-shaped groove 13 is formed in the end face of the synthetic resin 8 on the opening side of the stator 3, and an O-ring 12 is mounted in the groove 13, and the lid 11 is bolted through the O-ring 12. And so on. A bearing 15 is fitted in a mounting hole 14 formed in the center of the lid 11, and the bearing 15 rotatably supports the other end of the shaft 2 of the rotor 1.

The stator 3 is housed in a cylindrical case 17 having a bottom. The inner peripheral surface of the case 17 is brought into close contact with the outer end surface of the yokes 4, 4.
The case 4 and the case 17 constitute a magnetic circuit of the stepping motor M.

The stepping motor M constructed as described above has a lid 11 and a gas shut-off section 31 provided on a gas shut-off section 31 which is provided with a large diameter in the middle of a gas supply pipe (fluid pipe) 30.
Is tightly attached to the flange portion 32 with a bolt or the like with a sealing member 33 such as packing interposed. Shaft 2 protruding into gas shut-off part 31
A feed screw 35 is formed at the distal end of the valve body 36, and a female screw 37 of a valve element 36 is screwed to the feed screw 35. The valve body 36 is prevented from rotating in the circumferential direction of the shaft 2 and is reciprocally movable in the axial direction, whereby the valve body 36 moves in the axial direction of the shaft 2 with the rotation of the shaft 2. ing. A pipe 30A which is a gas supply pipe 30 on the side for introducing gas into the gas shut-off section 31;
The valve seat 40 is formed in the gas shut-off part 31 in. The gas that has entered the gas shut-off unit 31
30B which is a gas supply pipe 30 on the side from which gas is released
Get out of.

In the gas shut-off valve configured as described above, when an earthquake is detected, the stepping motor M operates, and when the shaft 2 of the stepping motor M makes a predetermined rotation, the valve body 36 is moved to the valve seat 40. Line 30 that moves toward and seats on the valve seat 40 and is part of the gas supply line 30.
Block A. In this gas shut-off valve, the valve element 36 is separated from the valve seat 40 by reversing the rotation of the stepping motor M, and the original state is easily restored.

In the stepping motor M configured as described above, the stator 3 has a sealing property so as to have a sealing property.
Since the synthetic resin 8 is integrally formed on the stator 3 and the lid 11 is airtightly attached to the stator 3 via the O-ring 12, the gas supply pipe 3 passes through the bearing 15 of the lid 11.
It is possible to completely prevent the gas that has entered the stepping motor M from the gas interrupting section 31 in the middle from leaking outside through the spaces between the yokes 4 and 4 or between the stator 3 and the lid 11.

Furthermore, conventionally, the case 17 and the coils 7, 7
Since there was a narrow gap between them and only air interposed therebetween, there was a possibility that the winding of the coil 7 might be broken by a lightning surge. However, in the above-described stepping motor M, the outer circumference of the coil 7 was made of synthetic resin. Since the synthetic resin 8 is interposed between the coils 7, 7 and the inner peripheral surface of the case 17, the insulation performance is improved because the cover 8 covers the coil 7, so that the lightning surge prevents the stepping motor M from being damaged. Becomes possible. Further, since the stator 3 has a configuration in which the yokes 4 and 4 are integrated with the synthetic resin 5 and the coils 7 and 7 are wound around the outer periphery, positioning and fixing between the yokes can be performed accurately and easily. It becomes possible.

In the above embodiment, the case where the present invention is used for a gas cutoff valve has been described. However, the present invention is not limited to this. For example, the present invention can be used for a valve of an outdoor unit of an air conditioner or a hot water valve of a radiator.

[0015]

As described above, in the valve driving motor with improved sealing according to the first or second aspect of the present invention, the stator is provided so that the stator has sealing. Since the synthetic resin is integrally molded and the lid is attached to the stator via a sealing member, a fluid such as gas which has entered the motor from the fluid line through the bearing of the lid flows between the yoke or between the stator and the lid. Leakage to the outside through the space can be completely prevented. In addition, when synthetic resin is integrally molded with the stator, if the outer periphery of the coil is covered with the synthetic resin, the synthetic resin will be interposed between the coil and the inner peripheral surface of the case, improving insulation performance. Therefore, it is possible to prevent the motor from being damaged by the lightning surge. In the valve drive motor with improved sealing according to the present invention, the stator is formed by integrating the yoke with a synthetic resin and winding a coil around the outer periphery of the yoke. There is an advantage that positioning and fixing between them can be performed accurately and easily.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a gas shutoff valve as an example of a valve according to the present invention.

[Explanation of symbols]

 M Stepping motor (motor) 1 Rotor 2 Shaft 3 Stator 4 Yoke 5 Synthetic resin 7 Coil 8 Synthetic resin 11 Lid 12 O-ring (sealing member) 15 Bearing 17 Case 30 Gas supply pipe (fluid pipe) 36 Valve

Claims (2)

[Claims] 1. A motor used for a valve interposed in a fluid pipe and closing the fluid pipe by a valve element provided on a rotating shaft, comprising: a rotor having the shaft; A stator on which a coil is wound and covers the rotor with a gap therebetween, a case for housing the stator, and a bearing for closing an opening of the stator and rotatably supporting the shaft of the rotor are mounted. And a synthetic resin is integrally molded with the stator so that the stator has a sealing property,
A valve driving motor with improved sealing performance, wherein the lid is attached to the stator via a sealing member. 2. The motor according to claim 1, wherein the yoke is integrated with a synthetic resin, and a coil is wound around an outer periphery of the yoke.