Patent Description:
In general, a ball valve is a type of opening/closing means widely used to supply or block a working fluid flowing through a pipeline coupled to both ends of the valve body to the required place by automatically rotating the ball installed inside the ball valve by driving the motor to open and close the pipeline.

A conventional ball valve actuator connects a motor shaft of a gear motor and an output shaft of a ball valve with a cam, and applies a sensor or a step motor to rotate the output shaft by an intended angle. In this case, a physical stopper is applied to limit the rotation angle of the output shaft.

However, when the torque of the motor is applied while the gear is in contact with the stopper, there is a problem in that the gear is damaged.

In order to solve this, in <CIT>, the motor is controlled to stop rotating in a state in which the gear is in contact with the stopper through the limiter switch.

In this case, as a configuration of a separate sensor for detecting that the gear is in contact with the stopper, a separate limiter switch, and a separate PCB board for a stop signal are added, there was a problem in that the size of the product increases and the manufacturing cost increases.

<CIT> discloses a valve device comprising an actuator and a ball valve connected to the actuator. The actuator further comprises a housing supporting an electric motor and an output shaft, a joint provided between the output shaft and a ball valve operating shaft, and a yoke provided between the housing and the valve body.

The problem to be solved by the present disclosure is to provide a valve actuator capable of preventing a gear from being damaged when a torque of a motor is applied while the gear is in contact with a stopper.

In addition, it is to provide a valve actuator capable of preventing a gear from being damaged without the configuration of a separate sensor for detecting that the gear is in contact with the stopper, a separate limiter switch, or a separate PCB board for a stop signal.

In addition, it is to provide a valve actuator applicable to a DC motor that is cheaper than an AC motor.

In addition, it is to provide a valve actuator capable of reducing the size of the product and reducing the manufacturing cost.

In addition, it is to provide a reusable valve actuator by pressing and turning the output shaft to be in external contact with the released gears.

A valve actuator according to an aspect of the present disclosure for achieving the above object may comprise a housing, a motor disposed on the housing, a driving gear coupled to a motor shaft of the motor, a transmission gear which is engaged with the driving gear and rotates according to a predetermined gear ratio when the driving gear rotates, an output shaft including a main body and one or more protrusions radially protruding from the main body, an output gear coupled to the output shaft and engaged with the transmission gear, a stopper disposed in the housing and limiting rotation of the output gear, and an elastic member disposed between a lower portion of the one or more protrusions and a lower plate of the housing.

In this case, an upper plate of the housing may include a first hole overlapping the main body in a vertical direction, and one or more second holes extending in a radial direction from the first hole, and when the output shaft rotates by a predetermined angle, the main body is configured to pass through the first hole by the elastic member, the one or more protrusions are configured to pass through the one or more second holes, and the output gear is configured to be disengaged from the transmission gear.

Through this, when the torque of the motor is applied while the output gear and the stopper are in contact, since the output gear is released from the transmission gear, it is possible to prevent the driving gear, the transmission gear, and the output gear from being damaged.

In addition, it is possible to prevent the gear from being damaged without the configuration of a separate sensor for detecting that the output gear is in contact with the stopper, a separate limiter switch, or a separate PCB board for a stop signal. Through this, it is possible to reduce the size of the product and reduce the manufacturing cost.

In addition, the one or more protrusions may be plural and include a first protrusion and a second protrusion spaced apart from the first protrusion in the circumferential direction. Circumferential angles of the first protrusion, the second protrusion, and first and second separation spaces located between the first protrusion and the second protrusion may be <NUM> degrees, respectively. In this case, circumferential angles of the one or more second holes, and spaces spaced apart between the plurality of second holes may be <NUM> degrees, respectively. Through this, it is possible to improve the easiness of manufacturing the output shaft.

In addition, the one or more protrusions may be plural and include first to fourth protrusions spaced apart from each other in the circumferential direction. Circumferential angles of the first to fourth protrusions and spaces spaced apart between the first to fourth protrusions may be <NUM> degrees, respectively. In this case, a circumferential angle of each of the one or more second holes may be <NUM> degrees. Circumferential angles of spaces spaced apart between the plurality of second holes may be <NUM> degrees, respectively. Through this, it is possible to improve the easiness of manufacturing the output shaft.

In addition, the motor may be a DC motor. In other words, since it can be applied to a DC motor that is cheaper than an AC motor, the manufacturing cost of the product can be reduced.

In addition, the main body of the output shaft may include a groove formed at an upper end. Through this, it is possible to reuse it by pressing and turning the output shaft through a tool such as a screwdriver to be in external contact with the released transmission gear and output gear.

In addition, at least a portion of upper ends of the plurality of protrusions may have a tapered or curved shape. Through this, the plurality of protrusions may easily pass through the plurality of second holes by the elastic member.

In addition, when the output shaft rotates by the predetermined angle, an upper region of the output gear may be in contact with the upper plate of the housing. Through this, it is possible to prevent the output shaft from being separated from the housing.

In addition, an upper end of the main body of the output shaft may be disposed above an upper end of the plurality of protrusions. Through this, it is possible to provide a space in which the external contact of the transmission gear and the output gear may be released.

A valve actuator according to an aspect of the present disclosure for achieving the above object may comprise a housing, a motor disposed on the housing, a driving gear coupled to a motor shaft of the motor, an output shaft including a main body and a plurality of protrusions radially protruding from the main body and spaced apart from each other in a circumferential direction, an output gear coupled to the output shaft and in external contact with the driving gear, a stopper disposed in the housing and limiting a rotation radius of the output gear, and an elastic member disposed between a lower portion of the plurality of protrusions and a lower plate of the housing.

In this case, an upper plate of the housing may include a first hole overlapping the main body in a vertical direction, and a plurality of second holes extending in a radial direction from the first hole, and when the output shaft rotates by a predetermined angle, the main body passes through the first hole by the elastic member, the plurality of protrusions passes through the plurality of second holes, and the output gear is released from the driving gear.

In addition, the plurality of protrusions may include a first protrusion and a second protrusion spaced apart from the first protrusion in the circumferential direction, and circumferential angles of the first protrusion, the second protrusion, and first and second separation spaces between the first protrusion and the second protrusion may be <NUM> degrees, respectively. In this case, circumferential angles of the plurality of second holes, and spaces spaced apart between the plurality of second holes may be <NUM> degrees, respectively. Through this, it is possible to improve the easiness of manufacturing the output shaft.

In addition, the plurality of protrusions may include first to fourth protrusions spaced apart from each other in the circumferential direction, and circumferential angles of the first to fourth protrusions and spaces spaced between the first to fourth protrusions may be <NUM> degrees, respectively. In this case, a circumferential angle of each of the plurality of second holes may be <NUM> degrees, and circumferential angles of spaces spaced apart between the plurality of second holes may be <NUM> degrees, respectively. Through this, it is possible to improve the easiness of manufacturing the output shaft.

In addition, at least a portion of upper ends of the plurality of protrusions may be formed in a tapered or curved shape. Through this, the plurality of protrusions may easily pass through the plurality of second holes by the elastic member.

Through the present disclosure, it is possible to provide a valve actuator capable of preventing a gear from being damaged when a torque of a motor is applied while the gear is in contact with a stopper.

In addition, it is possible to provide a valve actuator capable of preventing the gear from being damaged without the configuration of a separate sensor for detecting that the gear is in contact with the stopper, a separate limiter switch, or a separate PCB board for a stop signal.

In addition, it is possible to provide a valve actuator applicable to a DC motor that is cheaper than an AC motor.

In addition, it is possible to provide a valve actuator capable of reducing the size of the product and reducing the manufacturing cost.

In addition, it is possible to provide a reusable valve actuator by pressing and turning the output shaft to be in external contact with the released gears.

Hereinafter, embodiments disclosed in the present disclosure will be described in detail with reference to the accompanying drawings, however, regardless of the reference numerals, the same or similar components will be given the same reference numerals and redundant description thereof will be omitted.

In describing the embodiments disclosed in the present disclosure, when a component is referred to as being "connected" or "accessed" to other component, it may be directly connected or accessed to the other component, however, it may be understood that other components may be present in the middle.

In addition, in describing the embodiments disclosed in the present disclosure, when it is determined that the detailed description of the related known technology may obscure the subject matter of the embodiments disclosed in the present disclosure, the detailed description thereof will be omitted. In addition, the accompanying drawings are only for easily understanding the embodiments disclosed in the present disclosure, the present disclosure is not limited by the accompanying drawings.

On the other hand, terms of disclosure may be replaced with terms such as document, specification, description.

<FIG> is a front view of a ball valve and a valve actuator according to an embodiment of the present disclosure. <FIG> is a perspective view of a valve actuator according to an embodiment of the present disclosure. <FIG> is an exploded perspective view of a valve actuator according to an embodiment of the present disclosure. <FIG> are perspective views in which some components of a valve actuator according to an embodiment of the present disclosure are removed. <FIG> is a plan view of a partial configuration of a valve actuator according to an embodiment of the present disclosure. <FIG> are operation diagrams according to an embodiment of the present disclosure. <FIG> is a perspective view of a modified example of some configuration of a valve actuator according to an embodiment of the present disclosure. <FIG> are operation diagrams of a modified example of a valve actuator according to an embodiment of the present disclosure. <FIG> is a perspective view of a modified example of an output gear and an output shaft of a valve actuator according to another embodiment of the present disclosure. <FIG> is an exploded perspective view of a ball valve according to an embodiment of the present disclosure. <FIG> are operation diagrams of a ball valve according to an embodiment of the present disclosure.

Referring to <FIG>, a valve actuator <NUM> according to an embodiment of the present invention includes a housing <NUM>, a motor <NUM>, a driving gear <NUM>, transmission gears <NUM>, <NUM>, <NUM>, an output gear <NUM>, an output shaft <NUM>, an elastic member <NUM>, and a stopper <NUM>, but may be implemented except for some of these configurations, and does not exclude additional configurations other than this.

The valve actuator <NUM> may be coupled to an upper portion of a plate <NUM> coupled to an upper portion of a ball valve <NUM>. The output shaft <NUM> of the actuator <NUM> may be coupled to a stem <NUM> of the ball valve <NUM>. As the output shaft <NUM> of the actuator <NUM> rotates, the stem <NUM> rotates, and a ball <NUM> of the ball valve <NUM> rotates to open and close the ball valve <NUM>.

For example, referring to <FIG>, the ball <NUM> of the ball valve <NUM> may include a coupling groove to which a lower portion of the stem <NUM> is coupled, and a long hole <NUM>. In this case, when the long hole <NUM> of the ball <NUM> is not disposed in a traveling direction of a flow path due to the rotation of the output shaft <NUM> and the stem <NUM>, the ball valve <NUM> may be closed.

Referring to <FIG>, the long hole <NUM> of the ball <NUM> in the basic state may be placed in the traveling direction of the flow path in the ball valve <NUM>. In this case, the fluid passing through the inside of the ball valve <NUM> may pass through the long hole <NUM>.

Referring to <FIG>, as the output shaft <NUM> rotates, the stem <NUM> and the ball <NUM> rotate so that the long hole <NUM> may not be placed in the traveling direction of the flow path in the ball valve <NUM>. In this case, since the fluid passing through the inside of the ball valve <NUM> does not pass through the long hole <NUM>, the ball valve <NUM> may block the fluid passing through the inside of the ball valve <NUM>.

The ball valve <NUM> may include a stem fixing portion <NUM> for coupling the stem <NUM> and an O-ring <NUM> disposed under the stem <NUM>.

The housing <NUM> may be formed in a hexahedral shape. The housing <NUM> may form the exterior of the valve actuator <NUM>. The housing <NUM> may be disposed on one side of the ball valve <NUM>. The housing <NUM> may be disposed on the ball valve <NUM>. The motor <NUM>, the driving gear <NUM>, the transmission gears <NUM>, <NUM>, <NUM>, the output gear <NUM>, the output shaft <NUM>, the elastic member <NUM>, and the stopper <NUM> is disposed in the housing <NUM>.

The housing <NUM> includes an upper plate <NUM>. The motor <NUM> may be coupled to the upper plate <NUM> of the housing <NUM>. The upper plate <NUM> of the housing <NUM> may be penetrated by a motor shaft of the motor <NUM>. The upper plate <NUM> of the housing <NUM> includes holes <NUM> and <NUM> that vertically overlap the output shaft <NUM>.

The holes <NUM> and <NUM> may include a first hole <NUM> and a plurality of second holes <NUM> extending radially or horizontally from the first hole <NUM>.

The first hole <NUM> overlaps a main body of the output shaft <NUM> in a vertical direction. The first hole <NUM> may be formed in a shape corresponding to the cross-sectional shape of the main body of the output shaft <NUM>. In one embodiment of the present disclosure, the first hole <NUM> is described as an example formed in a circular shape, but the present disclosure is not limited thereto and may be variously changed according to the cross-sectional shape of the main body of the output shaft <NUM>.

The plurality of second holes <NUM> may vertically overlap a plurality of protrusions <NUM> of the output shaft <NUM>. The plurality of second holes <NUM> may be formed in a shape corresponding to the cross-sectional shape of the plurality of protrusions <NUM> of the output shaft <NUM>. The number of the plurality of second holes <NUM> may be formed to correspond to the number of the plurality of protrusions <NUM> of the output shaft <NUM>.

The motor <NUM> is disposed on the housing <NUM>. The motor <NUM> may be coupled to the upper plate <NUM> of the housing <NUM>, and the motor shaft of the motor <NUM> may pass through the housing <NUM> and be disposed inside the housing <NUM>. Through this, space efficiency may be improved. The driving gear <NUM> is coupled to the motor shaft of the motor <NUM>.

The motor <NUM> may be a DC motor. The motor <NUM> may be an AC motor, but in a case of the DC motor, it is possible to reduce the manufacturing cost of the valve actuator <NUM> compared to the AC motor. In a case of the DC motor, the accuracy of rotation number control is lower than that of the AC motor, but it can be supplemented by the physical stopper <NUM> of the valve actuator <NUM>.

The driving gear <NUM> is coupled to the motor shaft of the motor <NUM>. The driving gear <NUM> may rotate in one direction when the motor shaft of the motor <NUM> rotates in one direction, and rotate in the other direction when the motor shaft rotates in the other direction. The driving gear <NUM> may be in external contact with the transmission gears <NUM>, <NUM>, and <NUM>. The driving gear <NUM> may be an external gear.

The transmission gears <NUM>, <NUM>, <NUM> may be in external contact with the driving gear <NUM>. The transmission gears <NUM>, <NUM>, and <NUM> may rotate according to a predetermined gear ratio when the driving gear <NUM> rotates. The transmission gears <NUM>, <NUM>, and <NUM> may be in external contact with the output gear <NUM>. The transmission gears <NUM>, <NUM>, and <NUM> may reduce the speed of the driving gear <NUM> by a predetermined gear ratio and transmit it to the output gear <NUM>. Through this, the transmission gears <NUM>, <NUM>, and <NUM> may increase the torque transmitted from the driving gear <NUM> and transmit it to the output gear <NUM>.

The transmission gears <NUM>, <NUM>, <NUM> may include a first gear <NUM>, a second gear <NUM>, and a third gear <NUM>.

The first gear <NUM> may be in external contact with the driving gear <NUM>. The first gear <NUM> may be in external contact with the second gear <NUM>. The first gear <NUM> may be in external contact with the driving gear <NUM> to be rotated at a predetermined gear ratio with respect to the driving gear <NUM>, and may be in external contact with the second gear <NUM> to rotate the second gear <NUM> at a predetermined gear ratio with respect to the first gear <NUM>.

The first gear <NUM> may include a first external gear <NUM> and a second external gear <NUM>.

The first external gear <NUM> may be in external contact with the driving gear <NUM>. Through this, the first gear <NUM> may rotate at a predetermined gear ratio with respect to the driving gear <NUM>. The first external gear <NUM> may be disposed on one side of the second external gear <NUM>. For example, the first external gear <NUM> may be disposed above the second external gear <NUM>.

The second external gear <NUM> may be vertically spaced apart from the first external gear <NUM>. The second external gear <NUM> may be disposed on the other side of the first external gear <NUM>. For example, the second external gear <NUM> may be disposed under the first external gear <NUM>. Through this, space efficiency can be improved. A radial size of the second external gear <NUM> may be smaller than a radial size of the first external gear <NUM>. The second external gear <NUM> may be in external contact with the second gear <NUM>. The second external gear <NUM> may rotate the second gear <NUM> at a predetermined gear ratio with respect to the first gear <NUM>.

The second gear <NUM> may be in external contact with the first gear <NUM>. The second gear <NUM> may be in external contact with the third gear <NUM>. The second gear <NUM> may be in external contact with the first gear <NUM> to be rotated at a predetermined gear ratio with respect to the first gear <NUM>, and may be in external contact with the third gear <NUM> to rotate the third gear <NUM> at a predetermined gear ratio with respect to the second gear <NUM>.

The second gear <NUM> may include a third external gear <NUM> and a fourth external gear <NUM>. The third external gear <NUM> may be in external contact with the second external gear <NUM> of the first gear <NUM>, and the fourth external gear <NUM> may be in external contact with the third gear <NUM>. The third external gear <NUM> and the fourth external gear <NUM> may be vertically spaced apart from each other. Through this, space efficiency can be improved. A radial size of the fourth external gear <NUM> may be smaller than a radial size of the third external gear <NUM>.

The third gear <NUM> may be in external contact with the second gear <NUM>. The third gear <NUM> may be in external contact with the output gear <NUM>. The third gear <NUM> may be in external contact with the second gear <NUM> to be rotated at a predetermined gear ratio with respect to the second gear <NUM>, and may be in external contact with the output gear <NUM> to rotate the output gear <NUM> at a predetermined gear ratio with respect to the third gear <NUM>.

The third gear <NUM> may include a fifth external gear <NUM> and a sixth external gear <NUM>. The fifth external gear <NUM> may be in external contact with the fourth external gear <NUM> of the second gear <NUM>, and the sixth external gear <NUM> may be in external contact with the output gear <NUM>. The fifth external gear <NUM> and the sixth external gear <NUM> may be vertically spaced apart from each other. Through this, space efficiency can be improved. A radial size of the fifth external gear <NUM> may be greater than a radial size of the sixth external gear <NUM>.

In the embodiment of the present disclosure, the transmission gears <NUM>, <NUM>, <NUM> are described as an example consisting of three gears, but the transmission gears <NUM>, <NUM>, <NUM> may be understood to include one or more gears.

The output gear <NUM> may be in external contact with the transmission gears <NUM>, <NUM>, <NUM>. The output gear <NUM> may be coupled to the output shaft <NUM>. The output gear <NUM> may have a rotation radius limited by the stopper <NUM>. The output gear <NUM> may be rotated in one direction or the other direction by the transmission gears <NUM>, <NUM>, and <NUM> to rotate the output shaft <NUM> in one direction or the other direction.

The output shaft <NUM> may be disposed in the housing <NUM>. The output shaft <NUM> may pass through the housing <NUM>, and one end may be coupled to the output gear <NUM>, and the other end may be coupled to the stem <NUM> of the ball valve <NUM>. The output shaft <NUM> may be rotated in one direction or the other direction by the output gear <NUM> to rotate the stem <NUM> of the ball valve <NUM> in one direction or the other direction. Through this, the ball valve <NUM> may be opened and closed.

The output shaft <NUM> includes the main body, the plurality of protrusions <NUM> radially protruding from the main body and circumferentially spaced apart from the main body, a separation space <NUM> formed between the plurality of protrusions <NUM>, and a coupling portion <NUM> extending downward from the main body. The coupling portion <NUM> may be formed to be smaller than the radius of the main body of the output shaft <NUM>. The coupling portion <NUM> may be formed in a cylindrical shape.

The main body of the output shaft <NUM> may be formed in a cylindrical shape. The main body of the output shaft <NUM> may vertically overlap the first hole <NUM>. The cross-sectional shape of the main body of the output shaft <NUM> may be formed to have a shape corresponding to the shape of the first hole <NUM>.

The plurality of protrusions <NUM> may protrude from the main body in a radial direction. Each of the plurality of protrusions <NUM> may be formed in an arc shape. The plurality of protrusions <NUM> may be spaced apart from each other in the circumferential direction. Each of the plurality of protrusions <NUM> may be formed in a shape corresponding to each of the plurality of second holes <NUM>.

When the output shaft <NUM> is rotated by a predetermined angle by the output gear <NUM>, the output gear <NUM> may be in contact with the stopper <NUM> to limit the rotation radius. In this case, the main body of the output shaft <NUM> passes through the first hole <NUM> of the upper plate <NUM> of the housing <NUM> by the elastic member <NUM>, and the plurality of protrusions <NUM> pass through the plurality of second holes <NUM>. That is, the output shaft <NUM> moves upward so that the output gear <NUM> may be released from external contact with the transmission gears <NUM>, <NUM>, and <NUM>. Through this, when the torque of the motor <NUM> is applied while the output gear <NUM> is in contact with the stopper <NUM>, since the output gear <NUM> is released from external contact with the transmission gears <NUM>, <NUM>, <NUM>, it is possible to prevent the driving gear <NUM>, the transmission gears <NUM>, <NUM>, <NUM>, and the output gear <NUM> from being damaged.

In addition, since it is possible to prevent the driving gear <NUM>, the transmission gears <NUM>, <NUM>, <NUM>, and the output gear <NUM> from being damaged without the configuration of a separate sensor for detecting that the output gear <NUM> is in contact with the stopper <NUM>, a separate limiter switch, or a separate PCB board for a stop signal, it is possible to reduce the size of the product and reduce the manufacturing cost.

The main body of the output shaft <NUM> may include a groove (not shown) formed on an upper end or upper surface. The groove of the main body of the output shaft <NUM> may be concave downwardly from the upper end or upper surface of the main body. Through this, it is possible to reuse the valve actuator <NUM> by pressing and turning the output shaft <NUM> through a tool such as a screwdriver to be in external contact with the released transmission gears <NUM>, <NUM>, <NUM> and output gear <NUM>.

Referring to <FIG>, at least a portion of an upper end or an upper region of the plurality of protrusions <NUM> may be formed in a tapered or curved shape. For example, a radially outer region of the upper region of the plurality of protrusions <NUM> may be a tapered region <NUM>. Through this, the plurality of protrusions <NUM> may easily pass through the plurality of second holes <NUM> by the elastic member <NUM>. In addition, when there is a tolerance between the plurality of protrusions <NUM> and the plurality of second holes <NUM>, this may be compensated.

When the output shaft <NUM> is rotated by a predetermined angle by the output gear <NUM>, the upper region or upper surface of the output gear <NUM> may be in contact with the lower surface of the upper plate <NUM> of the housing <NUM>. Through this, it is possible to prevent the output shaft <NUM> from being separated from the housing <NUM> by the elastic member <NUM>.

The upper end or upper surface of the main body of the output shaft <NUM> may be disposed above the upper end or upper surface of the plurality of protrusions <NUM>. Through this, it is possible to provide a space in which the external contact of the transmission gears <NUM>, <NUM>, <NUM> and the output gear <NUM> may be released.

The plurality of protrusions <NUM> may include a first protrusion and a second protrusion spaced apart from the first protrusion in the circumferential direction. Contrary to that shown in <FIG>, circumferential angles of the first protrusion and the second protrusion, and first and second separation spaces between the first protrusion and the second protrusion may be <NUM> degrees, respectively. In this case, circumferential angles of the plurality of second holes <NUM>, and spaces spaced apart between the plurality of second holes <NUM> may be <NUM> degrees, respectively. Through this, it is possible to improve the easiness of manufacturing the output shaft <NUM>.

Referring to <FIG>, the plurality of protrusions <NUM> may include first to fourth protrusions <NUM>, <NUM>, <NUM>, and <NUM> spaced apart from each other in the circumferential direction. Circumferential angles of the first to fourth protrusions <NUM>, <NUM>, <NUM>, and <NUM> and spaces spaced apart between the first to fourth protrusions <NUM>, <NUM>, <NUM>, and <NUM> may be <NUM> degrees, respectively. In this case, a circumferential angle of each of the plurality of second holes <NUM> and <NUM> may be <NUM> degrees, and circumferential angles of spaces spaced apart between the plurality of second holes <NUM> and <NUM> may be <NUM> degrees, respectively. Through this, it is possible to improve the easiness of manufacturing the output shaft <NUM>. In this case, unlike described above, the number of the plurality of protrusions <NUM> may be four, and the number of the plurality of second holes <NUM> and <NUM> may be two.

The elastic member <NUM> may be disposed between a lower portion of the plurality of protrusions <NUM> and a lower plate of the housing <NUM>. For example, the elastic member <NUM> may be a spring surrounding the coupling portion <NUM>. In a state in which the transmission gears <NUM>, <NUM>, <NUM> and the output gear <NUM> are in external contact with each other, the elastic member <NUM> may be in a compressed state between the lower portion or lower surface of the plurality of protrusions <NUM> and an upper surface of the lower plate of the housing <NUM>. In a state in which the output gear <NUM> and the output shaft <NUM> rotate by a predetermined angle so that the output gear <NUM> is in contact with the stopper <NUM>, the elastic member <NUM> pushes the plurality of protrusions <NUM> upward so that the main body of the output shaft <NUM> and the plurality of protrusions <NUM> may pass through the first hole <NUM> and the plurality of second holes <NUM>, respectively.

The stopper <NUM> may be disposed in the housing <NUM>. The stopper <NUM> may be formed on an inner surface of the housing <NUM>. The stopper <NUM> may be disposed within the rotation radius of the output gear <NUM>. The stopper <NUM> may limit a rotation angle of the output gear <NUM>.

Referring to <FIG>, an operation of the valve actuator <NUM> according to an embodiment of the present disclosure will be described.

Assuming that <FIG> is in an initial state, in the initial state, the inside of the ball valve <NUM> may be in an open state. In this case, only a portion of the plurality of protrusions <NUM> of the main body <NUM> may vertically overlap the plurality of second holes <NUM>, or the plurality of protrusions <NUM> may not vertically overlap the plurality of second holes <NUM>.

As shown in <FIG>, when the motor <NUM> rotates the driving gear <NUM> in one direction, the first gear <NUM> in external contact with the driving gear <NUM> is rotated in the other direction, the second gear <NUM> in external contact with the first gear <NUM> is rotated in one direction, the third gear <NUM> in external contact with the second gear <NUM> is rotated in the other direction, the output gear <NUM> in external contact with the third gear <NUM> is rotated in one direction, and the output shaft <NUM> coupled to the output gear <NUM> is rotated in one direction to make the inside of the ball valve <NUM> closed. In this case, the rotation radius of the output gear <NUM> is limited by the stopper <NUM> to prevent damage to the ball valve <NUM>.

Even when the inside of the ball valve <NUM> is in a closed state, the motor <NUM> may continue to operate. In this case, the plurality of protrusions <NUM> of the output shaft <NUM> and the plurality of second holes <NUM> of the upper plate <NUM> of the housing <NUM> overlap in a vertical direction, and the elastic member <NUM> pushes the plurality of protrusions <NUM> upward so that the main body of the output shaft <NUM> and the plurality of protrusions <NUM> may pass through the first hole <NUM> and the plurality of second holes <NUM>, respectively. That is, since the external contacts of the output gear <NUM> and the transmission gears <NUM>, <NUM>, and <NUM> are released, it is possible to prevent damage to the driving gear <NUM>, the transmission gears <NUM>, <NUM>, <NUM>, and the output gear <NUM> that may occur when the motor <NUM> continues to operate.

Referring to <FIG>, an operation of a modified example of the valve actuator <NUM> according to an embodiment of the present disclosure will be described.

Referring to <FIG>, in the initial state in which the inside of the ball valve <NUM> is in an open state, at least a portion of the plurality of protrusions <NUM> of the main body <NUM> may not vertically overlap the plurality of second holes <NUM>.

Referring to <FIG>, when the motor <NUM> rotates the driving gear <NUM> in the other direction, the first gear <NUM> in external contact with the driving gear <NUM> is rotated in one direction, the second gear <NUM> in external contact with the first gear <NUM> is rotated in the other direction, the third gear <NUM> in external contact with the second gear <NUM> is rotated in one direction, the output gear <NUM> in external contact with the third gear <NUM> is rotated in the other direction, and the output shaft <NUM> coupled to the output gear <NUM> is rotated in the other direction to make the inside of the ball valve <NUM> closed. In this case, the rotation radius of the output gear <NUM> is limited by the stopper <NUM> to prevent damage to the ball valve <NUM>.

Referring to <FIG>, when the motor <NUM> rotates the driving gear <NUM> in one direction, the first gear <NUM> in external contact with the driving gear <NUM> is rotated in the other direction, the second gear <NUM> in external contact with the first gear <NUM> is rotated in one direction, the third gear <NUM> in external contact with the second gear <NUM> is rotated in the other direction, the output gear <NUM> in external contact with the third gear <NUM> is rotated in one direction, and the output shaft <NUM> coupled to the output gear <NUM> is rotated in one direction to make the inside of the ball valve <NUM> closed. In this case, the rotation radius of the output gear <NUM> is limited by the stopper <NUM> to prevent damage to the ball valve <NUM>.

Even when the inside of the ball valve <NUM> is in a closed state, the motor <NUM> may continue to operate. In this case, the plurality of protrusions <NUM> of the output shaft <NUM> and the plurality of second holes <NUM> of the upper plate <NUM> of the housing <NUM> may overlap in the vertical direction. For example, the first protrusion <NUM>, the fourth protrusion <NUM>, and a space between the first protrusion <NUM> and the fourth protrusion <NUM> may all overlap <NUM>-<NUM> protrusion <NUM> in the vertical direction, and the second protrusion <NUM>, the third protrusion <NUM>, and a space between the second protrusion <NUM> and the third protrusion <NUM> may all overlap <NUM>-<NUM> protrusion <NUM> in the vertical direction.

In this case, the elastic member <NUM> pushes the plurality of protrusions <NUM> upward so that the main body of the output shaft <NUM> and the plurality of protrusions <NUM> pass through the first hole <NUM> and the plurality of second holes <NUM>, respectively. That is, since the external contacts of the output gear <NUM> and the transmission gears <NUM>, <NUM>, and <NUM> are released, it is possible to prevent damage to the driving gear <NUM>, the transmission gears <NUM>, <NUM>, <NUM>, and the output gear <NUM> that may occur when the motor <NUM> continues to operate.

A valve actuator according to another embodiment of the present disclosure includes a housing <NUM>, a motor <NUM> disposed on the housing <NUM>, a driving gear <NUM> coupled to a motor shaft of the motor <NUM>, an output shaft <NUM> including a main body and a plurality of protrusions <NUM> radially protruding from the main body and spaced apart from each other in the circumferential direction, an output gear <NUM> coupled to the output shaft <NUM> and in external contact with the driving gear <NUM>, a stopper <NUM> disposed in the housing <NUM> and limiting a rotation radius of the output gear <NUM>, and an elastic member <NUM> disposed between a lower portion of the plurality of protrusions <NUM> and a lower plate of the housing <NUM>.

In this case, an upper plate <NUM> of the housing <NUM> may include a first hole <NUM> overlapping the main body of the output shaft <NUM> in the vertical direction, and a plurality of second holes <NUM> extending from the first hole <NUM> in the radial direction, and when the output shaft <NUM> is rotated by a predetermined angle, the main body of the output shaft <NUM> may pass through the first hole <NUM> by the elastic member <NUM>, the plurality of protrusions <NUM> may pass through the plurality of second holes <NUM>, and the output gear <NUM> may be released from the external contact with the driving gear <NUM>.

That is, the valve actuator according to another embodiment of the present disclosure (not claimed) may be interpreted as the transmission gears <NUM>, <NUM>, <NUM> are excluded from the valve actuator <NUM> according to an embodiment of the present disclosure.

Through this, it is possible to reduce the cost of the product by simplifying the configuration of the valve actuator.

Some or other embodiments of the present disclosure described above are not exclusive or distinct from one another. Some or other embodiments of the present disclosure described above may be used in combination or combined with each configuration or function.

For example, it means that configuration A described in specific embodiments and/or drawings and configuration B described in other embodiments and/or drawings may be combined. In other words, even when the combination between the components is not described directly, it means that the combination is possible except when it is described as not possible to combine.

Claim 1:
A valve actuator comprising:
a housing (<NUM>);
a motor (<NUM>) disposed on the housing (<NUM>);
a driving gear (<NUM>) coupled to a motor shaft of the motor (<NUM>);
a transmission gear (<NUM>, <NUM>, <NUM>) which is engaged with the driving gear (<NUM>) and rotates according to a predetermined gear ratio when the driving gear (<NUM>) rotates;
an output shaft (<NUM>) including a main body and one or more protrusions (<NUM>) radially protruding from the main body;
an output gear (<NUM>) coupled to the output shaft (<NUM>) and being engaged with the transmission gear (<NUM>, <NUM>, <NUM>); characterised by further comprising
a stopper (<NUM>) disposed in the housing (<NUM>) and configured to limit rotation of the output gear (<NUM>); and
an elastic member (<NUM>) disposed between a lower portion of the one or more protrusions (<NUM>) and a lower plate of the housing (<NUM>),
wherein an upper plate (<NUM>) of the housing (<NUM>) includes a first hole (<NUM>) overlapping the main body in a vertical direction, and one or more second holes (<NUM>) extending in a radial direction from the first hole (<NUM>), and
wherein when the output shaft (<NUM>) rotates by a predetermined angle, the main body is configured to pass through the first hole (<NUM>) by the elastic member (<NUM>), the one or more protrusions (<NUM>) are configured to pass through the one or more second holes (<NUM>) by the elastic member (<NUM>), and the output shaft (<NUM>) is configured to move upward in said vertical direction by the elastic member (<NUM>) so that the output gear (<NUM>) is disengaged from the transmission gear (<NUM>, <NUM>, <NUM>).