Patent Description:
Refrigerant is essentially used in an air conditioner which is one of the air conditioning devices, and Freon gas used as the refrigerant acts as a factor of global warming.

Therefore, in recent years, refrigerant has been developed, which is not concerned with the global warming, and the newly developed refrigerant does not act as the factor of the global warming, but there is a risk of a fire in the case of refrigerant leakage due to an ignition propensity, and as a result, a valve actuator for automatically actuating a valve for interrupting leakage in the case of the refrigerant leakage has been developed.

As a valve installed between an outdoor unit and an indoor unit of the air conditioner and preventing the refrigerant leakage, a ball valve is primarily used, and as illustrated in <FIG>, a ball valve <NUM> includes a ball <NUM> with a path, a pipe <NUM> into which the ball <NUM> is inserted, a stem <NUM> connected to the pipe <NUM>, a seal member <NUM> installed in the stem <NUM>, and a stem fixation bolt <NUM>.

A valve actuator for controlling the ball valve having such a configuration generally includes a motor and a gear assembly, and controls the valve by controlling rotation of the motor by using a sensor such as a limit switch, etc., or controlling the rotation of the motor by using a step motor.

As an example, Korean Patent Application <CIT> (hereinafter, referred to as "prior patent") discloses a valve actuator configured in such a manner that when a projection portion of an output gear connected to the stem of the ball valve among a plurality of gears provided in the gear assembly rotates at <NUM> degrees or more, an electronic limit switch is pressed to stop the motor.

However, the valve actuator of the prior patent having the electronic limit switch has a problem in that sensors' peculiar instability in a harsh environment.

<CIT> discloses a valve provided with a metering gate and a diverter gate.

The present disclosure provides a valve actuator capable of securing durability and driving stability.

The present disclosure also provides a valve actuator removing instability of an electronic sensor.

The present disclosure also provides a valve actuator which need not include a separate PCB for a motor stop signal.

The objects of the present disclosure are not limited to the above-mentioned objects, and other objects and advantages of the present disclosure that are not mentioned can be understood by the following description, and will be more clearly understood by embodiments of the present disclosure.

Further, it will be readily appreciated that the objects and advantages of the present disclosure can be realized by means and combinations shown in the claims.

The present invention is defined by the appended independent claim, and preferred aspects of the present invention are defined by the appended dependent claims. A valve actuator according to an exemplary embodiment of the present, not falling into the scope of the appended independent claim, disclosure includes: a motor; a gear assembly including an input gear rotated by driving force of the motor, an output gear receiving rotational force of the input gear, and at least one power transmission gear transmitting the rotational force of the input gear to the output gear; a valve output shaft actuated to close a path of a valve; and a selective power transmission unit selectively transmitting the rotational force of the output gear to the valve output shaft, and the selective power transmission unit includes a cam portion provided in at least one of the output gear and the valve output shaft.

According to the invention the cam portion in the form of a single cam portion is provided in each of the output gear and the valve output shaft.

Preferably the output gear further includes a tooth portion positioned to be higher than the cam portion provided in the output gear, a height difference between the cam portion and the tooth portion is formed to be equal to or larger than a thickness of the cam portion, and a thickness of the valve output shaft is formed to equal to the thickness of the cam portion provided in the output gear or smaller than the thickness of the cam portion of the output gear.

Preferably the valve actuator further comprises a case in which the motor, the gear assembly and the valve output shaft are installed.

The motor is installed outside the case, and the gear assembly and the valve output shaft are installed inside the case.

Preferably the power transmission gear includes a first gear coupled to the input gear, a second gear coupled to the first gear, and a third gear coupled to each of the second gear and the output gear.

Preferably the first gear includes a first tooth portion coupled to a tooth portion of the input gear and a second tooth portion positioned at a lower side of the first tooth portion of the first gear, the second gear includes a first tooth portion coupled to the second tooth portion of the first gear, and a second tooth portion positioned at an upper side of the first tooth portion of the second gear, and the third gear includes a first tooth portion coupled to the second tooth portion of the second gear, and a second tooth portion positioned at the lower side of the first tooth portion of the third gear and coupled to the tooth portion of the output gear.

Preferably the tooth portion of the output gear and the cam portion provided in the output gear are positioned in opposite directions based on a shaft of the output gear.

In a second aspect which is not claimed, the cam portion is provided in any one of the output gear and the valve output shaft, and a groove portion coupled to the cam portion is provided in the other one of the output gear and the valve output shaft.

The output gear of the valve actuator according to the second aspect further includes a tooth portion positioned to be higher than the cam portion or the groove portion provided in the output gear, a height difference between the cam portion or the groove portion and the tooth portion is formed to be equal to or larger than a thickness of the cam portion or the groove portion, and a thickness of the valve output shaft is formed to equal to the thickness of the cam portion or the groove portion provided in the output gear or smaller than the thickness of the cam portion or the groove portion of the output gear.

The valve actuator of the valve actuator according to the second aspect further comprises a case in which the motor, the gear assembly and the valve output shaft are installed.

The motor of the valve actuator according to the second aspect is installed outside the case, and the gear assembly and the valve output shaft are installed inside the case.

The power transmission gear of the valve actuator according to the second aspect includes a first gear coupled to the input gear, a second gear coupled to the first gear, and a third gear coupled to each of the second gear and the output gear.

The first gear of the valve actuator according to the second aspect includes a first tooth portion coupled to the tooth portion of the input gear and a second tooth portion positioned at a lower side of the first tooth portion of the first gear, the second gear includes a first tooth portion coupled to the second tooth portion of the first gear and a second tooth portion positioned at an upper side of the first tooth portion of the second gear, and the third gear includes a first tooth portion coupled to the second tooth portion of the second gear and a second tooth portion positioned at the lower side of the first tooth portion of the third gear and coupled to the tooth portion of the output gear.

The tooth portion of the output gear and the cam portion or the groove portion provided in the output gear are positioned in opposite directions based on a shaft of the output gear.

According to the present invention, driving force of a motor is transmitted to a valve output shaft through a gear assembly and a valve is closed, and then the driving force of the motor is not transmitted to the valve output shaft by the selective power transmission unit to prevent damage to the gear assembly and/or the motor due to over-torque and apply a motor of a type in which an RPM control is inaccurate.

In addition, since the electronic sensor is not used, the instability of the electronic sensor can be removed, and a separate PCB for a motor stop signal need not be provided, thereby increasing durability, and improving complexity and material cost.

In addition to the above-described effects, the specific effects of the present disclosure will be described below together while describing the specific matters for the present disclosure.

The present disclosure will be described more fully hereinafter with reference to the accompanying <FIG>, in which exemplary embodiments of the invention are shown. The present disclosure can be realized in various different forms, and is not limited to the exemplary embodiments described herein.

A part irrelevant to the description will be omitted to clearly describe the present disclosure, and the same elements will be designated by the same reference numerals throughout the specification. Further, some exemplary embodiments of the present disclosure will be described in detail with reference to illustrative <FIG>.

When reference numerals refer to components of each drawing, although the same components are illustrated in different drawings, the same components are denoted by the same reference numerals as possible. Further, in describing the present disclosure, a detailed description of known related configurations and functions may be omitted to avoid unnecessarily obscuring the subject matter of the present disclosure.

In describing the component of the present disclosure, when it is disclosed that any component is "connected", "coupled", or "linked" to other components, it should be understood that another component may be "interposed" between respective components or the respective components may be "connected", "coupled", or "linked" through another component.

<FIG> is a diagram illustrating a coupling state of a valve actuator and a ball valve according to an exemplary embodiment of the present disclosure and <FIG> is an exterior perspective view of the valve actuator illustrated in <FIG>.

As illustrated, in order to install the valve actuator <NUM> in the ball valve <NUM>, a plate <NUM> may be installed above the ball valve <NUM>, and the valve actuator <NUM> may be coupled to the plate <NUM>.

The plate <NUM> may be fixed to an upper end of the ball valve <NUM> by a fastening member such as a fastening screw, etc., and the valve actuator <NUM> may be fixed to the plate <NUM> by the fastening member such as the fastening screw, etc..

The valve actuator <NUM> includes a case <NUM>.

The case <NUM> provides a space in which a motor <NUM> and a gear assembly provided in the valve actuator <NUM> are installed, the motor <NUM> is installed on an upper surface of the case <NUM> outside the case <NUM>, and the gear assembly is disposed in an internal space of the case <NUM>.

The motor <NUM> may be a motor of a type in which RPM control is accurate. However, this is not required, and the motor <NUM> may be a motor of a type in which the RPM control is inaccurate. That is, since the valve actuator according to the exemplary embodiment of the present disclosure may selectively transmit power by a mechanical structure, damage to the gear assembly may be prevented and the ball valve may be accurately controlled while using the motor of the type in which the RPM control is inaccurate.

<FIG> is an exploded perspective view of the valve actuator illustrated in <FIG>, <FIG> is a perspective view illustrating a coupling state of a gear assembly illustrated in <FIG>, and <FIG> is a bottom perspective view of the gear assembly illustrated in <FIG>.

In addition, <FIG> and <FIG> are diagrams illustrating an actuation state of the valve actuator, and <FIG> is a diagram illustrating a cam engagement state within a normal actuation range and <FIG> is a diagram illustrating a state in which cam engagement is released.

As illustrated, the gear assembly includes an input gear <NUM> coupled and/or connected to a rotational shaft of the motor <NUM> and receiving the driving force of the motor <NUM>, an output gear <NUM> coupled to a valve output shaft <NUM> and transmitting rotational force of the input gear <NUM> to the valve output shaft <NUM>, and at least one power transmission gear transmitting the rotational force of the input gear <NUM> to the output gear <NUM>.

Hereinafter, it will be described as an example that the power transmission gear is constituted by first to third gears, but the number of power transmission gears may be appropriately changed.

In addition, in the exemplary embodiment, while the rotational force of the input gear is transmitted to the output gear through the power transmission gear, a speed is reduced by the gear assembly or the power transmission gear.

The input gear <NUM> includes a tooth portion 131a.

A first gear <NUM> coupled to the input gear <NUM> includes a first tooth portion 133a physically directly coupled to the toot portion 131a of the input gear <NUM> and a second tooth portion 133b disposed below the first tooth portion 133a on an axis of the first gear <NUM>.

A first tooth portion 134a of a second gear <NUM> is physically directly coupled to the second tooth portion 133b of the first gear <NUM>, and the second tooth portion 134b is positioned above the first tooth portion 134a on the axis of the second gear <NUM>.

In addition, a third gear <NUM> includes a first tooth portion 135a physically directly coupled to the second tooth portion 134b of the second gear <NUM>, and a second tooth portion 135b positioned below the first tooth portion 135a on the axis of the third gear <NUM>.

In addition, a tooth portion 132a of the output gear <NUM> is physically directly coupled to the second tooth portion 135b of the third gear <NUM>, and the output gear <NUM> further includes a cam portion 132c positioned in an opposite direction to the tooth portion 132a based on the axis.

The tooth portion 132a of the output gear <NUM> may be formed in an arc shape.

The tooth portion 132a of the output gear <NUM> is positioned to be higher than the cam portion 132c, and a height difference between the cam portion 132c and the tooth portion 132a is formed to be equal to or larger than a thickness of the cam portion 132c.

The valve output shaft <NUM> positioned adjacent to the output gear <NUM> includes a cam portion 140c which is actuated mutually with the cam portion 132c.

In addition, the valve output shaft <NUM> and the cam portion 140c is formed to be equal to the thickness of the cam portion 132c of the output gear <NUM> or smaller than the thickness of the cam portion 132c of the output gear <NUM>.

Accordingly, even though the valve output shaft <NUM> is positioned within a rotation radius of the output gear <NUM>, the valve output shaft <NUM> may interfere with rotation actuation of the output gear <NUM>.

The valve output shaft <NUM> is coupled to the stem <NUM> of the ball valve <NUM>.

In the exemplary embodiment, the cam portion 132c of the output gear <NUM> and the cam portion 140c of the valve output shaft <NUM> constitute the selective power transmission unit.

The "selective power transmission unit" which is actuated to selectively transmit the rotational force of the output gear <NUM> to the valve output shaft <NUM> includes a cam portion provided in at least one of the output gear <NUM> and the valve output shaft <NUM>, and is constituted by a cam portion 132c of the output gear <NUM> and a cam portion 140c of the valve output shaft <NUM> as illustrated in <FIG>.

Accordingly, when the motor <NUM> is actuated, the driving force of the motor <NUM> is transmitted to the output gear <NUM> sequentially through the input gear <NUM>, the first gear <NUM>, the second gear <NUM>, and the third gear <NUM>, and appropriate speed reduction is made during the power transmission process.

When the value actuator is within the normal actuation range, the cam portion 132c of the output gear <NUM> and the cam portion 140c of the valve output shaft <NUM> are maintained in contact with each other.

However, the cam portion 132c of the output gear <NUM> and the cam portion 140c of the valve output shaft <NUM> may be maintained slightly spaced apart from each other.

Here, the "normal actuation range of the valve actuator" means a state in which driving of the motor <NUM> is stopped and an initial state in which the motor <NUM> is driven in order to close the path by controlling the ball valve <NUM>.

When the gas leakage is detected while the valve <NUM> is being used, a driving signal is applied to the motor <NUM> and the motor <NUM> is thus driven, and the driving force of the motor <NUM> is transmitted to the output gear <NUM> sequentially through the input gear <NUM>, the first gear <NUM>, the second gear <NUM>, and the third gear <NUM>, and as a result, the output gear <NUM> is rotated in a counterclockwise direction.

When the output gear <NUM> is rotated in the counterclockwise direction, the cam portion 132c of the output gear <NUM> is also rotated in the counterclockwise direction together with the output gear <NUM>, and the rotational force of the output gear <NUM> is transmitted to the valve output shaft <NUM> through the cam portion 132c of the output gear <NUM> and the cam portion 140c of the valve output shaft <NUM>.

Accordingly, the valve output shaft <NUM> is rotated at approximately <NUM> degrees in a clockwise direction, and the path of the ball valve <NUM> is closed due to the rotation of the valve output shaft <NUM>.

In addition, after the valve output shaft <NUM> is rotated in the clockwise direction, the engagement of the cam portion 132c of the output gear <NUM> and the cam portion 140c of the valve output shaft <NUM> is released, and as a result, even though the driving of the motor <NUM> is not stopped, but continuously driven, the driving force of the motor <NUM> is not transmitted to the valve output shaft <NUM>.

Accordingly, the motor and/or the gear assembly are/is prevented from being damaged due to the over-torque.

In addition, since the valve actuator of the present disclosure uses a cam portion having a simple structure, the durability and the driving stability of the valve actuator are secured.

In addition, since the valve actuator of the present disclosure need not include a separate electronic switch and a separate PCB for the motor stop signal, the instability of the electronic switch or the electronic sensor is removed, and the complexity and the material cost of the device are improved.

Hereinabove, the valve actuator for controlling the ball valve provided in the air conditioner has been described, but the valve actuator according to the present disclosure may be used in a valve for controlling a path of gas or a fluid.

In the above-described exemplary embodiment, it is described as an example that the "selective power transmission unit" is constituted by the cam portion provided in the output gear and the cam portion provided in the valve output shaft, but according to a second aspect which is not claimed, the "selective power transmission unit" may be constituted by a cam portion provided in any one of the output gear and the valve output shaft, and a groove portion provided in the remaining one.

When this is described, the cam portion 132c is provided in the output gear <NUM>, and the groove portion 140d which is engaged with the cam portion 132c is provided in the valve output shaft <NUM>.

Accordingly, in the state illustrated in <FIG>, the cam portion 132c and the groove portion 140d are engaged, and in the state illustrated in <FIG>, the engagement of the cam portion 132c and the groove portion 140d is released.

Unlike this, although not illustrated, it is possible that the groove portion is provided in the output gear <NUM>, and the cam portion is also provided in the valve output shaft <NUM>.

Claim 1:
A valve actuator comprising:
a motor (<NUM>);
a gear assembly including an input gear (<NUM>) rotated by driving force of the motor (<NUM>), an output gear (<NUM>) receiving rotational force of the input gear (<NUM>), and at least one power transmission gear transmitting the rotational force of the input gear (<NUM>) to the output gear (<NUM>);
a valve output shaft (<NUM>) actuated to close a path of a valve; and
a selective power transmission unit selectively transmitting the rotational force of the output gear (<NUM>) to the valve output shaft (<NUM>),
wherein the selective power transmission unit includes a single cam portion (132c, 140c) provided in at least one of the output gear (<NUM>) and the valve output shaft (<NUM>),
characterized in that the single cam portion (132c, 140c) is provided in each of the output gear (<NUM>) and the valve output shaft (<NUM>).