Spring-return type actuator provided with speed reduction gear unit

Abstract

The present invention relates to a spring-return type actuator provided with a speed reduction gear unit. According to an embodiment of the present invention, disclosed is a spring-return type actuator in which, when power supply is interrupted, a driving shaft is automatically rotated and restored by a reel spring to drive objects to be controlled, such as valves and dampers. The spring-return type actuator is provided with the speed reduction gear unit, which provides a torque boosting function, separate from a planetary gear system that provides an operation control function for the restoring rotation, thus making it possible to provide a large force required for the restoring rotation of a large-capacity valve or damper without excessively increasing the number of turns of the reel spring.

Description

Spring return type actuator equipped with a reduction gear section

[0001] The present invention relates to a spring return type actuator equipped with a reduction gear section, wherein when the power supply is cut off, the drive shaft automatically returns to a return rotation by means of a reel spring to drive a control target such as a valve or damper, and the invention relates to a spring return type actuator equipped with a reduction gear section that provides a torque increase function separately from a planetary gear body that provides a motion control function for return rotation, so as to provide a large force required for the return rotation of a large-capacity valve or damper without excessively increasing the number of turns of the reel spring.

[0002] An actuator is a mechanical device used to move or control a system, and a spring-return type actuator is a prime mover that causes a pivot shaft to automatically rotate via a spring when the power supply is cut off, thereby opening valves or similar devices.

[0003] For example, a spring return valve actuator is designed so that the ventilation opening automatically opens when the valve is opened to prevent suffocation from smoke when the power supply is cut off due to a fire or other reasons.

[0004] The inventor has proposed a spring return type actuator capable of automatically restoring rotation when the power supply is cut off by using a planetary gear body and a reel spring through the previously registered Korean Patent No. 10-1130983 (March 21, 2012) and Korean Patent No. 10-1987891 (June 4, 2019).

[0005] Meanwhile, when the power to the motor is turned off due to a power outage or fire, for example, when a force of about 10 kgf is required for the restoration rotation of a valve or damper connected to the actuator, the force required for the restoration rotation can be easily provided using only the elastic restoring force of the reel spring.

[0006] However, in the case of a large-capacity valve or damper, a force of, for example, about 30 kgf may be required for the return rotation, and in order to provide the force required for the return rotation using only the elastic restoring force of the reel spring, a large-capacity reel spring must be manufactured by significantly increasing the number of turns of the reel spring.

[0007] However, there may be limitations in increasing the number of rotations of the reel spring due to limitations in the manufacturing process and product structure.

[0008] The present invention has been devised in consideration of the above-mentioned problems, and aims to provide a spring return type actuator equipped with a reduction gear unit configured to provide a torque increase function separately from a planetary gear unit that provides a motion control function for restoration rotation, so as to provide a large force required for the restoration rotation of a large-capacity valve or damper without excessively increasing the number of turns of the reel spring.

[0009] According to one aspect of the present invention for achieving the above-mentioned purpose, the invention comprises: a motor having a drive gear coupled coaxially to a rotating shaft; a planetary gear body including a sun gear drivenly connected to the drive gear through a drive gear train, a planetary gear provided on the outer side of the sun gear and gear-coupled thereto, a carrier coupled such that rotation occurs when the planetary gear revolves around the sun gear, and a ring gear provided on the outer side of the planetary gear and gear-coupled thereto; a rotating shaft configured to rotate integrally with the carrier and transmit the driving force of the motor to an output side; a reel spring installed on one side of the outer circumference of the rotating shaft and configured to convert and store the driving force of the motor into an elastic restoring force and to provide the elastic restoring force so as to enable the restoring rotation of the rotating shaft when the power to the motor is cut off; and a rotational locking means configured to be locked or unlocked on the outer surface of the ring gear. A spring return type actuator having a reduction gear unit is disclosed, characterized by being configured to include: a reduction gear unit coupled to the output side of the rotation shaft and further reducing the rotation of the rotation shaft and further increasing the torque to transmit it to the drive shaft.

[0010] Preferably, the reduction gear unit comprises an output side planetary gear body, an output side sun gear driven and connected coaxially with the rotation shaft, an output side planetary gear provided on the outside of the output side sun gear and geared, an output side carrier coupled to rotate integrally with the drive shaft and coupled so that rotation occurs when the output side planetary gear revolves around the output side sun gear, and an output side ring gear provided on the outside of the output side planetary gear and geared.

[0011] Preferably, the present invention further comprises a stopper that is provided on the drive shaft and rotates together in the same direction when the drive shaft rotates, and whose rotation is restricted by contact with a fixing bolt installed in an actuator casing, thereby limiting the rotation angle of the drive shaft to a certain range.

[0012] Preferably, the present invention comprises, wherein the rotation locking means comprises: a brake gear that is gear-coupled to an outer tooth surface formed on the outer side of the ring gear; an electronic brake in which a brake shaft is connected to the brake gear through a braking gear train and locks or unlocks the rotation of the brake shaft according to a power supply or cut-off state; and a governor in which a rotation shaft is connected to the brake shaft to control the rotational speed of the brake shaft.

[0013] Preferably, the governor comprises: a casing formed including a cylindrical side wall; a rotating shaft disposed along the vertical direction on the center side of the casing, rotatably supported based on the casing, and connected to and installed on the brake shaft to rotate together; A weight is disposed in the space between the inner surface of the side wall of the casing and the outer surface of the rotation axis, and is disposed such that a portion of the inner surface of the side wall formed to have a circular planar profile and the outer surface form a gap between them; and an elastic body is connected to the rotation axis to form the weight; wherein the centrifugal force received by the weight rotating together with the rotation axis changes according to the change in the rotational speed of the rotation axis, and the elastic body deforms according to the change in the centrifugal force, thereby changing the size of the gap between the inner surface of the side wall of the casing and the outer surface of the weight, and the viscous resistance force transmitted to the outer surface of the weight from the inner surface of the side wall of the casing through a viscous lubricant changes according to the change in the size of the gap, so that the rotational speed of the rotation axis is controlled.

[0014] According to another aspect of the present invention, a motor having a drive gear coupled coaxially to a rotational shaft; a planetary gear body comprising a sun gear drivenly connected to the drive gear through a drive gear train, a planetary gear provided on the outer side of the sun gear and gear-coupled thereto, a carrier coupled such that rotation occurs when the planetary gear revolves around the sun gear, and a ring gear provided on the outer side of the planetary gear and gear-coupled thereto; a rotating shaft configured to rotate integrally with the carrier and transmit the driving force of the motor to an output side; a reel spring installed on one side of the outer circumference of the rotating shaft and configured to convert and store the driving force of the motor into an elastic restoring force and to provide the elastic restoring force so as to enable the restoring rotation of the rotating shaft when the power to the motor is cut off; and a rotational locking means configured to be locked or unlocked on the outer surface of the ring gear. A spring return type actuator having a reduction gear unit is disclosed, characterized by being configured to include: a reduction gear unit comprising an output side planetary gear body that is coupled to the output side of the rotation shaft through an output side sun gear that is driven and connected coaxially with the rotation shaft, and further reduces the rotation of the rotation shaft and further increases the torque to transmit it to the drive shaft.

[0015] The present invention has the advantage of providing a large force required for the restoration rotation of a large-capacity valve or damper without excessively increasing the number of turns of the reel spring, by having a planetary gear body that provides a motion control function for restoration rotation and a reduction gear unit that provides a torque increase function separately, so that when the power supply is cut off, the drive shaft automatically restores and rotates by means of a reel spring to drive a control object such as a valve or damper.

[0016] In addition, the present invention is configured such that an upper planetary gear body and a lower output-side planetary gear body that provides the function of a reduction gear unit are installed coaxially, thereby optimizing installation space and providing a compact product structure.

[0017] FIG. 1 is a perspective view of a main part of a spring return type actuator according to an embodiment of the present invention.

[0018] FIG. 2 is another perspective view of a main part of a spring return type actuator according to an embodiment of the present invention.

[0019] FIG. 3 is a partially exploded perspective view of a main part of a spring return type actuator according to an embodiment of the present invention.

[0020] FIG. 4 is another partially exploded perspective view of the main part of a spring return type actuator according to an embodiment of the present invention.

[0021] FIG. 5 is a cross-sectional view of a spring return type actuator according to an embodiment of the present invention,

[0022] FIG. 6 is another cross-sectional view of a spring return type actuator according to an embodiment of the present invention,

[0023] FIG. 7 is a partial perspective view of a manual handle side of a spring return type actuator according to an embodiment of the present invention in a state where it is drivenly connected to a ring gear.

[0024] FIG. 8 is a partial cross-sectional view illustrating the installation state of a governor according to an embodiment of the present invention,

[0025] FIG. 9 is a perspective view of a governor according to an embodiment of the present invention,

[0026] FIG. 10 is a plan view of a governor according to an embodiment of the present invention,

[0027] FIG. 11 is a partial cross-sectional view of a governor according to an embodiment of the present invention.

[0028] The present invention may be implemented in various other forms without departing from its technical concept or main features. Accordingly, the embodiments of the present invention are merely examples in all respects and should not be interpreted restrictively.

[0029] Terms such as "first," "second," etc., are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component.

[0030] When it is stated that a component is "connected" or "joined" to another component, it may be directly connected or joined to that other component, or there may be other components in between.

[0031] The singular expressions used in this application include the plural expressions unless the context clearly indicates otherwise. In this application, terms such as "comprising," "having," or "having" are intended to express the existence of the components or combinations thereof described in the specification, and do not preclude the possibility that other components or features may exist or be added.

[0032]

[0033] Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings.

[0034] FIG. 1 is a perspective view of a main part of a spring return type actuator according to an embodiment of the present invention, FIG. 2 is another perspective view of a main part of a spring return type actuator according to an embodiment of the present invention, FIG. 3 is a partially exploded perspective view of a main part of a spring return type actuator according to an embodiment of the present invention, FIG. 4 is another partially exploded perspective view of a main part of a spring return type actuator according to an embodiment of the present invention, FIG. 5 is a cross-sectional view of a spring return type actuator according to an embodiment of the present invention, FIG. 6 is another cross-sectional view of a spring return type actuator according to an embodiment of the present invention, and FIG. 7 is a partial perspective view of a state in which the manual handle side of a spring return type actuator according to an embodiment of the present invention is driven and connected to a ring gear.

[0035] The spring return type actuator of the present embodiment is a spring return type actuator driven by a motor (15), and comprises a planetary gear body (30) including a sun gear (31) driven by the motor (15), a pivot shaft (41) that transmits the driving force of the motor (15), a reel spring (winding spring, 55) installed on one side of the outer surface of the pivot shaft (41) to store the driving force of the motor (15), and a rotation locking means configured to change the driving state (locked / unlocked state) of the planetary gear body (30) by being locked or unlocked to the outer tooth surface (35a) of the ring gear (35) of the planetary gear body (30) according to a change in the on / off state of the power supply. For example, the rotation locking means may be configured to include an electronic brake (60).

[0036] The above spring return type actuator may be, for example, a spring return valve actuator configured to open or close a valve by the rotation of a pivot shaft (41).

[0037] The rotational direction of the pivot shaft (41) driven by the motor (15) can be classified into a direction for opening the valve or a direction for closing the valve.

[0038] The above motor (15) has a drive gear (12) coupled coaxially to a rotation axis (11).

[0039] The above planetary gear assembly (30) includes a sun gear (31) that is driven and connected to the drive gear (12) through a drive gear train (13a, 13b, 13c), a planetary gear (33) that is provided on the outside of the sun gear (31) and gear-coupled thereto, a carrier (34) that is coupled to allow rotation to occur when the planetary gear (33) revolves around the sun gear (31), and a ring gear (35) that is provided on the outside of the planetary gear (33) and gear-coupled thereto. The drive gear train (13a, 13b, 13c) includes one or more gears and can be composed of a combination of various known gears.

[0040] For example, as illustrated in FIGS. 1 to 3 and FIGS. 5, when the actuator is driven in the power-on state, the rotation shaft (11) is rotated by the motor (15) and the drive gear (12) is rotated, and the drive gear (12) transmits driving force to the driven gear (13c) through a drive gear train (13a, 13b, 13c) in which a plurality of gears (13a, 13b, and 13c) are sequentially gear-coupled (and / or coaxially coupled).

[0041] The above-mentioned driven gear (13c) transmits driving force to the sun gear (31) coupled coaxially, and the sun gear (31) rotates.

[0042] At this time, the ring gear (35) maintains a rotation lock state by means of an electronic brake (60), and the rotation of the sun gear (31) is transmitted to the carrier (34) through the planetary gear (33), so that the carrier (34) inside the ring gear (35) rotates in the same direction as the sun gear (31).

[0043] The rotation of the pivot shaft (41) is achieved by the rotation of the carrier (34).

[0044] The above-mentioned pivot shaft (41) is configured to rotate integrally with the carrier (34) to transmit the driving force of the motor (15) to the output side.

[0045] The reel spring (55) is installed on one side of the outer surface of the pivot shaft (41) and is configured to convert and store the driving force of the motor (15) into an elastic restoring force and to provide the elastic restoring force so that the pivot shaft (41) can return to its original rotation when the power to the motor (15) is cut off.

[0046] When the rotational direction of the above-mentioned pivot shaft (41) is the valve closing direction, the reel spring (55) that stores the driving force of the above-mentioned motor (15) is wound while rotating partially in the same direction as the above-mentioned pivot shaft (41) rotates. Through this winding of the reel spring (55), the driving force of the above-mentioned motor (15) is converted into and stored as an elastic restoring force, and the wound state of the reel spring (55) is maintained in the valve closing state.

[0047] The above elastic restoring force is intended to enable the rotation of the rotation shaft (41) to return to normal rotation when the power of the motor (15) is turned off due to a power outage or fire, etc. When the rotation locking state of the ring gear (35) is released when the power is turned off, the elastic restoring force stored in the reel spring (55) is provided to the rotation shaft (41), thereby rotating the rotation shaft (41) in the reverse direction, so that the emergency opening state of the actuator valve is achieved.

[0048] The above brake gear (62) is gear-coupled to the outer tooth surface (35a) formed on the outer side of the ring gear (35).

[0049] The electronic brake (60) has a brake shaft (61) connected to the brake gear (62) via a braking gear train (63, 64), and locks or unlocks the rotation of the brake shaft (61) depending on the power supply or cut-off state. For example, the electronic brake (60) provides a locking / unlocking operation using an electromagnet (65 in FIG. 8).

[0050] The spring return type actuator of this embodiment is configured to include a reduction gear section.

[0051] The above reduction gear unit is coupled to the output side of the rotation shaft (41) and further reduces the rotation of the rotation shaft (41) and further increases the torque to transmit it to the drive shaft (141).

[0052] The above reduction gear unit can be implemented in the form of a reduction gear train in which two or more gears are combined to provide a reduction function, and preferably can be configured in the form of an output-side planetary gear body (130).

[0053] Referring to FIG. 4, the output side planetary gear body (130) comprises an output side sun gear (131) driven coaxially with the rotation shaft (41), an output side planetary gear (133) provided on the outside of the output side sun gear (131) and gear-coupled thereto, an output side carrier (134) coupled so that rotation occurs when the output side planetary gear (133) revolves around the output side sun gear (131) and coupled to rotate integrally with the drive shaft (141), and an output side ring gear (135) provided on the outside of the output side planetary gear (133) and gear-coupled thereto. For example, the rotation shaft (41) and the output side sun gear (131) may be formed integrally. For example, the output side ring gear (135) may be fixedly installed on the actuator casing (1).

[0054] The spring return type actuator of the present embodiment is configured to further reduce the rotation of the rotation shaft (41) and further increase the torque through the output side planetary gear body (130) and transmit it to the drive shaft (141).

[0055] Through the above configuration, the spring return type actuator of the present embodiment is configured to include an upper planetary gear body (30) and a lower output side planetary gear body (130).

[0056] The upper planetary gear body (30) provides a motion control function that enables the rotation of the rotation shaft (41) to be restored when the power of the motor (15) is turned off due to a power outage or fire.

[0057] The lower output-side planetary gear body (130) provides a torque-increasing function that further reduces the output rotation of the rotation shaft (41) and further increases the torque, which is then transmitted to the drive shaft (141). Through this, the drive shaft (141) provides a higher torque output to the outside compared to the rotation shaft (41).

[0058] For example, when the power of the motor (15) is turned off due to a power outage or fire, and a force of about 10 kgf is required for the restoration rotation of the valve or damper connected to the actuator, the force required for the restoration rotation can be easily provided using only the elastic restoring force of the reel spring (55).

[0059] However, in the case of a large-capacity valve or damper, a force of about 30 kgf may be required for the return rotation, and in order to provide the force required for the return rotation using only the elastic restoring force of the reel spring (55), the number of turns of the reel spring (55) must be greatly increased to produce a large-capacity reel spring.

[0060] However, there may be a limit to increasing the number of rotations of the reel spring (55) due to limitations in the manufacturing process and product structure.

[0061] Taking this into account, the spring return type actuator of the present embodiment is equipped with a lower output-side planetary gear body (130) that provides a torque increase function separately from the upper planetary gear body (30) that provides a motion control function for restoration rotation.

[0062] Through this configuration, the spring return type actuator of the present embodiment can provide a large force required for the restoration rotation of a large-capacity valve or damper without excessively increasing the number of rotations of the reel spring (55).

[0063] In particular, the spring return type actuator of the present embodiment is configured so that the upper planetary gear body (30) and the lower output side planetary gear body (130) are installed coaxially, thereby making the installation space efficient and providing a compact product structure.

[0064] Meanwhile, the spring return type actuator of the present embodiment is configured to include a stopper (52).

[0065] The stopper (52) is provided on the drive shaft (141) and rotates together in the same direction when the drive shaft (141) rotates, and its rotation is restricted by contact with the fixing bolt (6) installed on the actuator casing (1), thereby limiting the rotation angle of the drive shaft (141) to a certain range. Two fixing bolts (6) (6a, 6b) may be installed to restrict rotation at one side position and the other side position.

[0066] In the spring return type actuator of the present embodiment, the rotation shaft (41) of the planetary gear body (30) does not provide the function of the final output shaft, and the drive shaft (141) of the output-side planetary gear body (130) installed below it provides the function of the final output shaft, so the stopper (52) is provided on the drive shaft (141) to limit the rotation angle of the drive shaft (141) to a certain range.

[0067] Meanwhile, a rotation recognition shaft (38) is coupled to the upper central side of the rotation shaft (41), and a rotation status display plate (not shown in the symbol) is provided at the upper part of the rotation recognition shaft (38). Symbol 2 is a transparent window that allows the rotation status display plate to be viewed from the outside.

[0068] Meanwhile, the spring return type actuator of the present embodiment is configured to have a manual handle (77) so that the pivot shaft (41) of the actuator can be manually rotated when the power is off.

[0069] To this end, the spring return type actuator is further configured to include a variable worm shaft (70) and a manual handle (77) coupled coaxially to the variable worm shaft (70).

[0070] For example, the manual handle (77) is linked to the variable worm shaft (70) by a hinge pin (75). For example, the variable worm shaft (70) is installed to enable gear coupling on the outside of the ring gear (35) and is configured to be separated or coupled to the outside of the ring gear by linking at one end with an eccentric cam (73) that rotates by a lever (71).

[0071] The detailed configuration of a spring return type actuator not described in this embodiment can be understood by referring to Korean Registered Patent No. 10-1130983 (March 21, 2012) and Korean Registered Patent No. 10-1987891 (June 4, 2019), which were previously registered by the inventors.

[0072]

[0073] Meanwhile, the spring return type actuator of the present embodiment includes a governor (100).

[0074] A governor is a control device used to maintain the rotational speed of an engine at a constant value, and it is mandatory to install it in machines that require the prime mover to be operated within a specific speed range, such as generators.

[0075] FIG. 8 is a partial cross-sectional view illustrating the installation state of a governor according to an embodiment of the present invention, FIG. 9 is a perspective view of a governor according to an embodiment of the present invention, FIG. 10 is a plan view of a governor according to an embodiment of the present invention, and FIG. 11 is a partial cross-sectional view of a governor according to an embodiment of the present invention.

[0076] Referring to FIG. 8, the governor (100) of the spring return type actuator of the present embodiment has a rotation shaft (104) connected to the brake shaft (61) so that the rotation speed (Vr) of the brake shaft (61) is controlled. Reference numeral 120 in FIG. 8 is a connecting shaft that connects the rotation shaft (104) of the governor (100) to the brake shaft (61).

[0077] The governor (100) of the present embodiment controls the rotational speed (Vr) by reducing the rotational speed (Vr) through the viscous resistance force (Fr) when the rotational speed (Vr) of the brake shaft (61) increases through the rotational speed control operation described below. The spring return type actuator of the present embodiment controls the rotational speed of the brake shaft (61) coupled to the rotational shaft (104) of the governor (100) so that it does not exceed a certain value through the rotational speed control operation, thereby providing the effect of preventing damage to the device due to an excessive increase in rotational speed. In particular, by reducing the rotational speed (Vr) through the viscous resistance force (Fr), it prevents wear and damage to the control element, thereby providing good durability and ease of maintenance.

[0078] More specifically, the governor (100) of the present embodiment comprises a casing (102), a rotating shaft (104), a weight (106), and an elastic body (108). For example, the casing (102), the rotating shaft (104), the weight (106), and the elastic body (108) may be made of a metal material.

[0079] The above casing (102) is configured to include a cylindrical side wall (102-1).

[0080] The above-described rotation axis (104) is positioned along the vertical direction (UD) on the center side of the casing (102), is rotatably supported based on the casing (102), and is connected to and installed on an object requiring control of rotational speed (Vr) so as to rotate together with the object. For example, the rotation axis (104) is rotatably supported on the casing (102) through an upper bearing (B) and a lower bearing (B).

[0081] The above weight (106) is disposed in the space between the inner surface (102a) of the side wall portion (102-1) of the casing (102) and the outer surface (104a) of the rotation axis (104), and is disposed in such a state that a portion of the inner surface (102a) of the side wall portion (102-1), which is formed to have a circular planar profile, and the outer surface (106a) form a gap (t) between them.

[0082] For example, the weight body (106) is formed such that its outer surface (106a) has a planar profile in the shape of an arc, and forms a mutual gap (t) in the shape of an arc with a portion of the inner surface (102a) of the side wall (102-1) which has a planar profile in the shape of a circle.

[0083] Preferably, the weights (106) are installed in a plurality of numbers, and the plurality of weights (106-1, 106-2) are arranged symmetrically around the rotation axis (104). In this embodiment, two weights (106) are installed in a 180-degree direction.

[0084] The above elastic body (108) is combined by connecting the above weight body (106) to the above rotation axis (104).

[0085] The above configuration can be configured in detail as follows.

[0086] The above weight body (106) is formed to have an upper and lower width and has an outer surface (106a) having an arc-shaped planar profile, a first cross-section (106b) formed on one end of the arc shape, and a second cross-section (106c) formed on the other end of the arc shape.

[0087] Additionally, the rotation axis (104) is formed to have an extension portion (104-1) that extends radially outward in an upper and lower section corresponding to the upper and lower width of the weight body (106).

[0088] The elastic body (108) is formed in a plate shape arranged along the vertical direction (UD), such that one side is fixed to the first cross section (106b) of the weight body (106) and the other side is fixed to the extension (104-1) of the rotation axis (104). Preferably, the first cross section (106b) of the weight body (106) is a cross section that rotates ahead of the second cross section (106c) with respect to the rotation direction of the weight body (106).

[0089] Through the above configuration, the centrifugal force (Fc) received by the weight (106) rotating together with the rotation axis (104) changes according to the change in the rotational speed (Vr) of the rotation axis (104), and the elastic body (108) deforms according to the change in the centrifugal force (Fc), thereby changing the size of the mutual gap (t) formed between the inner surface (102a) of the side wall portion (102-1) of the casing (102) and the outer surface (106a) of the weight (106).

[0090] As a result, depending on the change in the size of the mutual gap (t), the viscous resistance force (Fr) transmitted from the inner surface (102a) of the side wall (102-1) of the casing (102) to the outer surface (106a) of the weight (106) through the viscous lubricant (110) changes, thereby controlling the rotational speed (Vr) of the rotation shaft (104). When the weight (106) rotates, the mutual gap (t) forms a passage gap through which the viscous lubricant (110) passes; therefore, as the size of the mutual gap (t) decreases, the viscous resistance force (Fr) increases.

[0091] The above viscous lubricant (110) is applied to the inner surface (102a) of the side wall portion (102-1) of the casing (102) and provides viscous resistance (Fr) in the arc-shaped mutual gap (t). For example, the viscous lubricant (110) may be grease, and it is also possible to use other types of viscous lubricants that can provide similar viscosity.

[0092] The rotational speed control operation of the governor (100) of this embodiment can be performed as follows.

[0093] As the rotational speed (Vr) of the above-mentioned rotational shaft (104) increases, the centrifugal force (Fc) received by the weight (106) rotating together with the above-mentioned rotational shaft (104) increases.

[0094] As the centrifugal force (Fc) increases, the elastic body (108) deforms, and the size of the gap (t) formed between the inner surface (102a) of the side wall (102-1) of the casing (102) and the outer surface (106a) of the weight (106) becomes smaller in at least a portion of the total gap. For example, referring to FIGS. 10 and FIGS. 11, the portion may be a section on the side of the first cross-section (106b) of the weight (106) and may be a section (or point) that forms the smallest gap among the outer surface (106a) having an arc-shaped planar profile of the weight (106).

[0095] As the size of the gap in at least a portion of the entire section of the mutual gap (t) becomes smaller, the viscous resistance (Fr) received by the outer surface (106a) of the weight body (106) from the inner surface (102a) of the side wall (102-1) of the casing (102) through the viscous lubricant (110) increases.

[0096] As a result, control is performed to reduce the rotational speed (Vr) of the above-mentioned rotation shaft (104).

[0097] Through the above configuration, the governor (100) of the present embodiment controls the rotational speed (Vr) of the rotation shaft (104) by utilizing viscous resistance (Fr) transmitted through a viscous lubricant (110) rather than direct friction of the speed control element, thereby preventing wear of the speed control element and providing an accurate rotational speed control function and high durability during long-term use.

[0098]

[0099] Although the present invention has been described with reference to preferred embodiments with reference to the accompanying drawings, it is evident to those skilled in the art that many diverse and obvious variations are possible from this description without departing from the scope of the invention. Accordingly, the scope of the invention should be interpreted by the claims described to include such many variations.

Claims

1. A motor in which a drive gear is coupled coaxially to a rotation axis; A planetary gear body comprising: a sun gear driven and connected to the driving gear through a driving gear train; a planetary gear provided on the outer side of the sun gear and gear-coupled thereto; a carrier coupled so that rotation occurs when the planetary gear revolves around the sun gear; and a ring gear provided on the outer side of the planetary gear and gear-coupled thereto; A pivot shaft configured to rotate integrally with the above carrier and transmit the driving force of the above motor to the output side; A reel spring installed on one side of the outer surface of the above-mentioned pivot shaft, configured to convert and store the driving force of the motor into an elastic restoring force and to provide the elastic restoring force so as to enable the pivot shaft to return to its original rotation when the power to the motor is cut off; Rotational locking means configured to be locked or unlocked on the outer surface of the above ring gear; and A spring return type actuator having a reduction gear unit, characterized by being configured to include a reduction gear unit coupled to the output side of the rotation shaft, which further reduces the rotation of the rotation shaft and further increases the torque to transmit it to the drive shaft.

2. In Paragraph 1, The above reduction gear unit is an output-side planetary gear body, An output-side sun gear driven coaxially with the above-mentioned rotational shaft, and An output planetary gear provided on the outer side of the output-side sun gear and gear-coupled thereto, and An output carrier coupled to rotate integrally with a drive shaft, wherein the output planetary gear is coupled to rotate when orbiting around the output sun gear, and A spring return type actuator having a reduction gear section characterized by being configured to include an output ring gear provided on the outer side of the output planetary gear and gear-coupled thereto.

3. In Paragraph 2, A spring return type actuator having a reduction gear section, further comprising a stopper provided on the drive shaft that rotates together in the same direction when the drive shaft rotates, and whose rotation is restricted by contact with a fixing bolt installed in the actuator casing to limit the rotation angle of the drive shaft to a certain range.

4. In Paragraph 1, The above-mentioned rotary locking means is, A brake gear that is gear-coupled to an outer tooth surface formed on the outer side of the above ring gear; An electronic brake in which a brake shaft is connected to the brake gear through a braking gear train and locks or unlocks the rotation of the brake shaft depending on the power supply or cut-off state; and A spring return type actuator having a reduction gear section, characterized by comprising a governor in which a rotating shaft is connected to and installed on the brake shaft to control the rotational speed of the brake shaft.

5. In Paragraph 4, The above governor is, A casing configured to include cylindrical sidewalls; A rotating shaft positioned along the vertical direction on the center side of the casing, rotatably supported based on the casing, and connected to and installed on the brake shaft to rotate together; A weight body disposed in the space between the inner surface of the side wall portion of the casing and the outer surface of the rotation axis, wherein a portion of the inner surface of the side wall portion formed to have a circular planar profile and the outer surface are disposed in a state where they are spaced apart from each other: and It includes an elastic body that connects the above weight body to the above rotational axis; A spring return type actuator equipped with a reduction gear unit, characterized in that the centrifugal force received by the weight body rotating together with the rotational shaft changes according to the change in the rotational speed of the rotational shaft, the elastic body deforms according to the change in the centrifugal force so that the size of the mutual gap formed between the inner surface of the side wall of the casing and the outer surface of the weight body changes, and the viscous resistance force transmitted to the outer surface of the weight body from the inner surface of the side wall of the casing through a viscous lubricant according to the change in the size of the mutual gap changes, thereby enabling control of the rotational speed of the rotational shaft.

6. A motor in which a drive gear is coupled coaxially to a rotation axis; A planetary gear body comprising: a sun gear driven and connected to the driving gear through a driving gear train; a planetary gear provided on the outer side of the sun gear and gear-coupled thereto; a carrier coupled so that rotation occurs when the planetary gear revolves around the sun gear; and a ring gear provided on the outer side of the planetary gear and gear-coupled thereto; A pivot shaft configured to rotate integrally with the above carrier and transmit the driving force of the above motor to the output side; A reel spring installed on one side of the outer surface of the above-mentioned pivot shaft, configured to convert and store the driving force of the motor into an elastic restoring force and to provide the elastic restoring force so as to enable the pivot shaft to return to its original rotation when the power to the motor is cut off; Rotational locking means configured to be locked or unlocked on the outer surface of the above ring gear; and A spring return type actuator having a reduction gear unit characterized by comprising: a reduction gear unit including an output side planetary gear body that is coupled to the output side of the rotation shaft through an output side sun gear driven coaxially with the rotation shaft, and further reduces the rotation of the rotation shaft and further increases the torque to transmit it to the drive shaft.

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