ACTUATOR

An actuator is provided, which includes: a rotary driver having a rotary shaft; a driving member coupled to the rotary shaft of the rotary driver and having a driving surface; a driven member, supported by the driving surface of the driving member, configured to linearly move along the rotary shaft by a rotation of the driving member without rotating around the rotary shaft.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority of Korean Patent Application No. 10-2016-0008378, filed on Jan. 22, 2016, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure generally relates to actuators, and more particularly, to an actuator to linearly move an object.

BACKGROUND ART

An actuator is a mechanical device used to move or control a system.

The term “actuator” is widely used to refer to a remote driving device that uses electricity, hydraulic power, compressed air, etc., and functions with an energy source in the form of electrical current, actuating hydraulic power, voltage, etc. A typical example of an actuator is a “solenoid” which converts a movement caused by such an energy source, for example, into a linear movement.

A solenoid is configured such that a coil is wound around a cylinder to generate a magnetic field therein to linearly move an active rod installed in the cylinder in one direction.

When an active rod is used, however, a constant electric power should be applied to the coil of the solenoid if the active rod is to be maintained at its displaced state.

Technical Problem

Accordingly, there is a need for an actuator which can maintain the linear movement after its driven member has moved linearly without applying an electric power to thereby minimize the energy consumption used to drive the actuator.

Technical Solution

In an exemplary embodiment, there is provided an actuator, which comprises: a rotary driver10having a rotary shaft11; a driving member30coupled to the rotary shaft11of the rotary driver10and having a driving surface20; a driven member40, supported by the driving surface20of the driving member30, configured to linearly move along the rotary shaft11by a rotation of the driving member30without rotating around the rotary shaft11.

The driving surface20may comprise a first supporting surface21, a first sloped surface22, a second support surface23, and a second sloped surface24continuously in sequence along a circumferential direction around the rotary shaft11. The first supporting surface21and the second supporting surface23may have a gap in height in a longitudinal direction of the rotary shaft11.

The driven member40may comprise a driven surface41which is in surface contact with the driving surface20so as to linearly move through a rotation of the driving member30.

The driven member40may comprise a driven surface41which matches in shape to the driving surface20.

The actuator may further comprise: a first rotation restrictor38which is connected to at least one of the rotary shaft11and the driving member30, and at least one second rotation restrictor58,59which allows the first rotation restrictor38to rotate within a predetermined angle of degrees.

The driving surface20may comprise at least one second supporting surface23which supports the driven member40at a location corresponding to a farthest point where the driven member40is displaced farthest from the rotary shaft11, and at least one sloped surface22,24, connected to the at least one second supporting surface23, which supports the driven member40at a location corresponding to a nearest point where the driven member40is displaced nearest from the rotary shaft11.

The actuator may further comprise a guide50which guides the driven member40to move linearly while preventing the driven member40from rotating around the rotary shaft11.

One of the guide50and the driven member40may be equipped with at least one guide groove formed along the linear movement of the driven member40, and the other of the guide50and the driven member40may be equipped with a protrusion which corresponds to the guide groove so that the protrusion moves linearly along the guide groove.

The actuator may further comprise an adhesion mechanism which keeps the driven surface41of the driven member40adhered to the driving surface20.

The adhesion mechanism may keep the driven surface41of the driven member40adhered to the driving surface20through a magnetic force or an elastic force.

The adhesion mechanism may comprise a magnet61installed in at least one of the driven member40and the driving member30.

The adhesion mechanism may comprise an elastic member which applies an elastic force to the driven member40against the driving member30.

Advantageous Effects

The actuator according to the present disclosure comprises: a rotary driver having a rotary shaft; a driving member coupled to the rotary shaft of the rotary driver and having a driving surface; a driven member, supported by the driving surface of the driving member, configured to linearly move along the rotary shaft by a rotation of the driving member without rotating around the rotary shaft, which simplifies the overall structure of the actuator and facilitates easy installation of the actuator to thereby significantly reduce the manufacturing cost.

The actuator according to the present disclosure comprises: a rotation restriction mechanism which includes a guide groove and a protrusion inserted into the guide groove, which simplifies the overall structure of the actuator to thereby significantly reduce the manufacturing cost.

The actuator according to the present disclosure can maintain the linear movement after its driven member has moved linearly without applying an electric power to thereby minimize the energy consumption to drive the actuator.

The actuator according to the present disclosure uses at least one of a magnet or an elastic member as an adhesion means to adhere the driven member to the driving member, which simplifies the overall structure of the actuator and facilitates easy installation of the actuator to thereby significantly reduce the manufacturing cost.

MODE FOR INVENTION

Hereinafter, an actuator in accordance with the present disclosure will be described in detail with reference to the accompanying drawings.

As illustrated inFIGS. 1 to 2C, the actuator in accordance with the present disclosure includes a rotary actuator10having a rotary shaft11, a driving member30coupled to the rotary shaft11of the rotary driving portion10and has a driving surface20, a driven member40which is supported by the driving surface of the driving member30and moved linearly along the longitudinal direction of the rotary shaft11by the rotation of the driving member30without being rotated around the rotary shaft11.

The actuator according to the present disclosure can be used as a device to linearly move an object coupled to the driven member40, such as a locking member of a door lock, a valve member of a valve, etc., by linearly moving the driven member40.

The rotary actuator10can have any configuration that generates rotary driving force around a rotary shaft11.

As an example, a rotary motor such as an electrical motor, a hydraulic motor, etc., can be used as the rotary driver10. A step motor which rotates with a predetermined degree of angle may be preferably used as a rotary motor.

As another example, the rotary driver10can be a combination of a permanent magnet coupled to a lower surface of the driving member30and a solenoid which rotates the i.e., the driving member30around the rotary shaft11.

On the other hand, the rotary driver10may have various configurations. For example, the rotary driver10may be configured such that the driving member30rotates with an interval of 180 degrees. In another configuration, the driving member30may rotate up to predetermined degrees and rotate back to the original position.

FIGS. 3A to 4Billustrate an example of a driving member30that rotates back and forth within a predetermined range of degrees, e.g., 180 degrees. As shown inFIGS. 3A to 4B, the actuator is equipped with a first rotation restrictor38which is coupled to one of the rotary shaft11and the driving member30, and at least one second rotation restrictor58,59which allows the first rotation restrictor38to rotate within a predetermined angle of degrees, e.g., 180 degrees.

The first rotation restrictor38and the at least one second rotation restrictor58,59may have any configurations which allow the driving member30to rotate back and forth within a range of 180 degrees.

For example, as illustrated inFIGS. 3A to 4B, the first rotation restrictor38may be a protrusion formed by projecting in a radial direction from the driving member30and the at least one second rotation restrictor58,59may be a stopper that restricts rotation of the protrusion formed on the driving member30.

The stopper may have various configurations. An exemplary configuration of the stopper is an incision provided at a guide50, which will be explained below.

The driving member30may also have various configurations. In one exemplary configuration, the driving member30may be coupled to the rotary shaft11of the rotary driver10and may have a driving surface20to support a driven surface41of a driven member40so as to linearly move the driven member40when the rotary driver10is rotated.

Specifically, the driving surface20may include a first supporting surface21, a first sloped surface22, a second supporting surface23, and a second sloped surface24in sequence, when viewed from above, around the rotary shaft11in a circumferential direction.

The first supporting surface21and the second supporting surface23may be formed such that they have a gap in heights in a longitudinal direction along the rotary shaft11.

The driving surface20may have a continuous surface including the first supporting surface21, the first sloped surface22, the second supporting surface23and the second sloped surface24in sequence such that, as the driving member30is rotated in accordance with the rotation of the rotary shaft11, each one of the first supporting surface21, the first sloped surface22, the second supporting surface23and the second sloped surface24supports the driven surface41of the driven member40sequentially.

As shown inFIG. 2C, the first supporting surface21, the first sloped surface22, the second supporting surface23and the second sloped surface24may be disposed sequentially to have a predetermined angle of degrees in between, e.g., 180 degrees, around the rotary shaft11.

The first supporting surface21and the second supporting surface23may be formed such that they have a gap in heights in the longitudinal direction along the rotary shaft11. In other words, the first supporting surface21is formed closer to the rotary driver10than the second supporting surface23. Then, the first sloped surface22and the second sloped surface24may be formed to connect the first supporting surface21and the second supporting surface23to constitute a single continuous driving surface20.

Each of the first supporting surface21and the second supporting surface23may have various shapes such as a concave surface, a convex surface, a planar surface, etc. While not limited thereto, each of the first supporting surface21and the second supporting surface23may be preferably a planar surface perpendicular to the rotary shaft11so as to maintain the supporting state of the driven surface41of the driven member40even if the rotary driver10is in an off state.

Each of the first sloped surface22and the second sloped surface24connects the first supporting surface21and the second supporting surface23. While not limited thereto, each of the first sloped surface22and the second sloped surface24may preferably be a curved surface having a varying curvature at the edge between the first supporting surface21or the second supporting surface23so as to form a continuous surface with the first supporting surface21and the second supporting surface23.

On the other hand, in case the rotary driver10rotates back and forth in a restricted angle, the rotation may be enough in either one direction between the first supporting surface21and the second supporting surface23. In such case, forming one of the first sloped surface22and the second sloped surface24may be enough.

Also, depending on the supporting configuration, one of the first supporting surface21and the second supporting surface23to support the driven member40may be omitted. For instance, the first supporting surface21may be omitted from the overall configuration.

Various shapes and structures for the driving member40, other than the ones illustrated inFIGS. 1 to 5B, may be also possible so long as the driving member40may support and linearly move the driven member40with a driving surface20formed thereon.

FIGS. 6 to 8Billustrate a modified embodiment of the embodiment illustrated inFIGS. 1 to 5B. The driving surface (20) of the driving member (30) may comprise at least one second supporting surface (23) which supports the driven member (40) at a location corresponding to a farthest point where the driven member (40) is displaced farthest from the rotary shaft (11), and at least one sloped surface (22,24), connected to the at least one second supporting surface (23), which supports the driven member (40) at a location corresponding to a nearest point where the driven member (40) is displaced nearest from the rotary shaft (11). The first supporting surface (21) of the previous embodiment may be omitted from the driving surface (20) of the driving member (30).

Specifically, the driven member40is disposed at the farthest location when the driven surface41, which is in surface contact with the driving surface20, is supported by the second support surface23, which will be explained later. The driven member40is disposed at the nearest location when the driven surface41has followed the sloped surfaces22,24by the rotation of the driving member30and a part of the driven member40is supported by the second supporting surface23. Through this mechanism, the driven member40is capable of linearly moving between the farthest and nearest points through the rotation of the driving member30.

The driven member40can have various configurations so long as it is capable of linearly moving along the rotary shaft11without rotating around the rotation axis11.

The driven member40is equipped with a driven surface51which is in surface contact with the driving surface20so as to linearly move through the rotation of the driving member30.

The driven member40is supported and in surface contact with the driving surface20of the driving member30. Accordingly, when the driving member30rotates, the driven member40can move linearly along the rotary shaft11depending on the shape of the driving surface20, i.e., following the first supporting surface21, the first sloped surface22, the second supporting surface23and the second sloped surface24sequentially.

On the other hand, in case the rotary driver10rotates in a restricted range of degrees, the driven surface51will move linearly only on the first supporting surface21, the first sloped surface22, and the second supporting surface23sequentially.

Also, the driven surface41may have any shapes so long as it can be supported by the driving surface20. It is preferable that the driven surface41be in point or line contact with the driving surface20with the minimum contact area to facilitate smooth movement along the driving surface20.

In case the driven surface41of the driven member40is in line contact with the driving surface20, it is preferable that the line contact be made in a radial direction around the rotary shaft11.

On the other hand, the remaining parts of the driven member40excluding the driven surface41are tailored so that, when the driven surface41is supported by the first supporting surface21, they are in contact or not in contact with the second supporting surface so as not to disturb the linear movement of the driven member40along the rotary shaft11.

As an example, as illustrated in the drawings, the driven member40may have a driven surface which matches in shape with the driving surface20.

Also, the driven member40may have various shapes and structures depending on the material of the driving member30and the shape of the driving surface20.

The driven member40, which is supported by the driving surface20when the driving member40rotates, should not be rotated to facilitate a linear movement. In order to achieve a linear movement, the driven member40is equipped with a guide50which guides the linear movement of the driven member40while preventing its rotation around the rotary shaft11.

The guide50can have various shapes and configurations which allow guidance of the linear movement of the driven member40while preventing its rotation around the rotary shaft11.

For example, while not limited thereto, the guide50may include at least one guide groove51formed along the direction of linear movement of the driven member41, as illustrated inFIGS. 2A to 3BandFIG. 5A. In such case, the driven member40may be equipped with a protrusion40formed on its wall so as to facilitate linear movement of the driven member40along the guide groove51.

An opposite configuration to the one depicted inFIGS. 2A to 3BandFIG. 5Amay also be possible. In other words, the driven member40may alternatively be equipped with a groove and the guide50may be equipped with a protrusion adapted to be inserted into the groove formed on the driven member40.

Various configurations of the driven member40may be possible for guiding the linear movement of the driven member40while preventing rotation of the driven member40around the rotary shaft11.

One example of such configuration may be the protrusion and the groove in which the protrusion is inserted, as illustrated inFIGS. 2A to 3BandFIG. 5A.

Another example of preventing rotation and guidance of linear movement of the driven member40is as follows: at least a part of the driven member40has a cylindrical shape, and a part of the cylindrical shape is incised to form at least one incision48having a plane at one side. Further, the guide50is equipped with a guide surface58which is in surface contact with the at least one incision48formed on the driven member48.

The guide50may have various other structures such as a housing structure, frame structure surrounding a side of the driven member40.

When the driven member40is supported by the second supporting surface23following the first supporting surface21, the driven member40is in a position illustrated inFIG. 2B, i.e., the driven member40is way from the rotary driver10. Subsequently, when the driven member40is supported by the first supporting surface21through additional rotation of the driving member30by way of the rotary driver10, the driven member40has returned to the state where the driven surface21of the driven member40is adhered to the driving surface20, i.e., the state illustrated inFIG. 2A.

For this, an adhesion means may be additionally provided to maintain the driven surface41of the driven member40to its adhered state to the driving surface20.

The adhesion means is provided to maintain the driven surface41of the driven member40to its adhered state to the driving surface20. The adhesion means may maintain the driven surface41of the driven member40to its adhered state through magnetic force or elastic force.

As a specific example, the adhesion means may include a magnet61installed on at least one of the driven member40and the driving member30.

More specifically, a magnet61may be installed on at least one of the driven member40and the driving member30, and an adhesion member62to attract the magnet61, i.e., a material which reacts with the magnetic force, such as a metallic material or magnet, can be installed at the other one.

In such case, the driven member40and the driving member30are preferably of materials which do not interact with the magnetic force, such as non-metallic materials or metals having non-magnetic characteristics.

In the embodiment illustrated inFIGS. 1 to 2C, the magnet61is of cylindrical shape, and is installed in the driven member40whereas the adhesion member62is installed at the driving member30. In such case, the driven member40is provided with a hole in which the adhesion member62may be inserted in the direction of the rotary shaft11so that the adhesion member62does not interfere with a linear movement of the driven member40.

The hole may be formed in a longitudinal direction of the rotary shaft11, and the magnet61may be embedded in the hole. The top portion of the adhesion member62may be inserted into the hole when the driven member40moves linearly.

The magnet61and the adhesion member62keep the driven surface41of the driven member40adhered to the driving surface20through the magnetic attraction.

Any configuration may be possible for the adhesion means using the magnetic force so long as the configuration keeps the driven surface41of the driven member40adhered to the driving surface20.

Another embodiment of the adhesion means includes an elastic member (not shown) which applies an elastic force to the driven member40against the driving member30.

Any configuration may be possible for the adhesion member so long as the adhesion member is capable of applying an elastic force to the driven member40against the driving member30.

In some applications, the adhesion means may be omitted depending on the usage of the actuator because a driving force to the driven member40is applied towards the driving member30.

As described above, the actuator having the aforementioned structure converts the rotational movement of the driving member30into the linear movement of the driven member40. The actuator having the aforementioned structure is applicable to various devices and systems, such as a linear motion generator of a door lock, a linear motion generator of an opening/closing member of an opening/closing valve, etc.