KR101767977B1

KR101767977B1 - Electric motor actuator with dc motor

Info

Publication number: KR101767977B1
Application number: KR1020150152908A
Authority: KR
Inventors: 강문식
Original assignee: (주) 파루
Priority date: 2015-11-02
Filing date: 2015-11-02
Publication date: 2017-08-14
Also published as: KR20170050869A

Abstract

An electric actuator using a DC motor is disclosed. The planetary reduction unit includes a planetary reduction unit having an output shaft and a planetary gear that receives a driving force from the power input unit to increase the torque, A speed increasing portion provided with a detachable cover for increasing the number of revolutions lowered in proportion to the torque and having one side opened and a screw shaft having a screw thread for changing the rotational motion transmitted from the speed increasing portion into a linear motion, And a cylinder portion provided with a displacement nut that is threadedly coupled with the screw shaft to move back and forth by rotation of the screw shaft so that it can be used in a structure having a large static frictional force and can be manufactured in a small size. It is possible to generate high torque, easy to install and maintain, and to use energy efficient DC motor It provides the same actuator.

Description

ELECTRIC MOTOR ACTUATOR WITH DC MOTOR [0002]

The present invention relates to an electric actuator, and more particularly, to an electric actuator using a direct current DC motor, which can be manufactured in a small size, and which is provided with a speed increasing portion for increasing the torque through a planetary deceleration, To an electric actuator using a DC motor which displaces the electric motor in the axial direction.

BACKGROUND ART Conventionally, as a means for conveying a material or the like, an electric actuator for displacing a slider for conveying the material by rotationally driving a feed screw by a rotational driving force of a rotary drive source such as a motor is widely known

In addition, the electric actuator is used in electric valves and dampers for controlling the flow rate of fluid such as hot water, cold water, steam, etc. In particular, an electric actuator for adjusting the opening degree of a valve or damper for controlling the flow rate of various fluids, A deceleration gear mechanism that decelerates the rotation of the drive motor to transmit the decelerated gear mechanism to a rotation shaft of a valve or a damper to be controlled, and a reduction gear mechanism that detects a current operation angle (or an operation range) of the rotation shaft And an operation angle detecting mechanism.

Further, as the reduction gear mechanism provided in the electric actuator, it is known that a planetary gear mechanism composed of a planetary gear, a planetary gear, and an internal gear is generally used in which a plurality of spur gears are usually stacked in multiple stages.

The rotation of the drive motor is reduced by the reduction gear mechanism to be transmitted to the shaft (rotation shaft) of the valve. However, the shaft of this valve is connected to the gear base at the final stage of the planetary gear mechanism, To the reloading through the transmission gear.

Generally, a planetary gear reducer is a gear train in which a sun gear, a ring gear, and planetary gears are arranged on a concentric line. In the case of the same transmission ratio, the volume is smaller than that of a gear train disposed in a speed reducer of another principle, And has been used in various fields requiring small size and light weight because of high transmission efficiency. In addition, the planetary gear reducer can be easily obtained at a low price because of mass production due to the known structure.

A general structure of an electric actuator including the above-described planetary gear reducer includes a motor generating a rotational force and a planetary gear reducer connected to a rotation shaft of the motor to increase a rotational force generated from the motor, And a link structure that receives the rotational force from the output shaft of the speed reducer and converts the rotational force into a linear reciprocating motion.

Specifically, the planetary gear reducer receives a high rotation speed of the motor and receives the rotation speed of the motor. With the sun gear as an input shaft, the number of rotations is reduced by the gear ratio of the planetary gear and the ring gear in the planetary gear reducer, . However, these high torques could be utilized, but the rotations were so low that they could not be applied to industrial machines.

Below I have listed the advantages and disadvantages of the planetary gear reducer below.

First of all, the advantages of the planetary gear reducer are as follows: First, the power transmission ratio per unit volume of planetary gears is small and lightweight. Second, since the transmission load and speed of each gear are reduced, the friction loss is small and the efficiency is increased. Third, the input shaft and the output shaft are coaxial. Fourth, two or more planetary gears can be combined. Fifth, because the power consumption is low, it is possible to generate profit by charging with self-generated power based on the photovoltaic power generation standard.

However, as a disadvantage of the planetary gear reducer, caution must be exercised when using it at high speed due to centrifugal force due to idle motion. Also, if the transmission power is too small, it will cost more than an ordinary transmission.

Therefore, it can not be used in industrial machines that require high speeds. However, it is not possible to use the electric actuators efficiently because of how to set the connection structure between the reducer and the motor, how to arrange the gears of the reducer, It can bring about an increase in the rotational force, and it is not necessarily impossible.

The problem of the arrangement of these gears is becoming important. Since the structure for connecting the rotation shaft of the motor to the planetary gear train and the structure for appropriately arranging and coupling the multi-planetary gear train are set, Is very important for an electric actuator.

Therefore, the present invention proposes a solution for how to transmit the high torque produced by the planetary gear reducer without dropping, and to increase the feed speed while maintaining the transmitted torque.

On the other hand, the planetary gear reducer input by using the AC motor is limited in the installation space due to an increase in the overall size, and the reduction ratio can not be maintained in an optimal state, so that the use thereof is limited. There is a problem that a defective rate due to manufacturing tolerance or assembly tolerance is generated.

Further, in the case of an electric actuator of an industrial machine which must obtain a large torque, an actuator using an AC power source is required because the horsepower must be high. A hydraulic actuator is required when a large power is required. This also takes a lot of space, and in particular, it is inconvenient to provide a separate power supply device, such as a hydraulic power supply, in order to have an AC power supply.

Korean Patent No. 10-1058404

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to solve the above-mentioned problems, and it is an object of the present invention to provide a planetary reduction gear unit including a planetary gear unit including a power input unit including a DC / DC motor, a planetary gear unit for receiving torque from the power input unit, A speed increasing portion provided with a removable cover to which a driving force is transmitted from the decelerating portion and which increases the number of revolutions lowered in proportion to an increased torque and which is opened at one side and a screw portion for changing the rotational motion transmitted from the speed increasing portion into a linear motion; And a cylinder portion having a screw nut rotatably screwed to the screw shaft and moving forward and backward by rotation of the screw shaft. The cylinder portion can be used in a structure having large static frictional force, It is possible to generate a higher initial torque than an AC motor produced in the same small size, And to provide an electric actuator using a DC motor having high energy efficiency, which is capable of obtaining an appropriate number of revolutions and torque through an accelerating portion and facilitating installation and maintenance.

In order to accomplish the above object, the present invention provides a planetary reduction gear mechanism including a planetary reduction unit having a power input unit including a DC-DC motor, a planetary gear that receives a driving force from the power input unit to increase torque, A speed increasing portion provided with a removable cover having one side opened and a screw shaft having a screw thread formed so as to convert a rotational motion transmitted from the speed increasing portion into a linear motion, And a cylinder portion having a displacement nut that is rotationally screwed to the screw shaft and performs a forward and backward movement by the rotation of the screw shaft. The speed increasing portion includes a drive pulley coupled with an output shaft of the planetary reduction portion, And a timing belt that is suspended between the driven pulley and the driven pulley, Greater than the relaxed diameter driven pulley, there is provided an electric actuator and with the drive pulley, the direct current motor is removable after opening the cover of the driven pulley.

Wherein a plurality of gear teeth are provided on the outer circumferential surface of the drive pulley and the driven pulley and gear teeth are formed on the inner circumferential surface of the timing belt to engage with gear teeth of the drive pulley and the driven pulley, Is transmitted to the drive pulley and is transmitted to the driven pulley by the timing belt to rotate the screw shaft and axially displace the displacement nut screwed to the screw shaft.

According to the electric actuator using the DC motor of the present invention described above, it is possible to manufacture a small-sized electric motor using a DC-DC motor, generate a torque higher than that of the initial AC motor at the same size, There is an effect that can be. Accordingly, in the case of an electric actuator of an industrial machine which must obtain a high torque, an actuator using an AC power source is mainly provided, but it is difficult to control the DC motor as compared with a DC motor, so that a separate inverter device must be provided. The problem can be solved. Therefore, it is easier to install and maintain the system than the hydraulic / pneumatic system, and has high energy efficiency.

In addition, a direct-current DC motor that generates a lower torque than the AC motor is used. After obtaining a high torque in the planetary deceleration section, the number of revolutions that have fallen away is increased through the speed increasing section and is adjusted to a desired number of revolutions and torque in the cylinder section. There is an effect that the hydraulic actuator can be replaced by a low-capacity direct current type power actuator. Accordingly, there is an effect that the power can be transmitted only by the battery without the need of a separate AC power source.

Further, the speed increasing portion of the present invention is provided with a detachable cover on the outer side so that the driving pulley and the driven pulley can be easily exchanged so that the required number of revolutions can be set precisely so that the number of revolutions can be transmitted in accordance with the required torque.

1 is a perspective view showing an electric actuator according to the present invention.
FIG. 2 is a perspective view showing a disassembled state of the electric actuator of FIG. 1. FIG.
Fig. 3 is a cross-sectional view taken along line CC of Fig. 1, and is a perspective view showing a knuckle joint disposed at an initial position.
Fig. 4 is a cross-sectional view taken along the line CC of Fig. 1, and is a perspective view showing a knuckle joint protruding to the outside.

For a better understanding of the present invention, a preferred embodiment of the present invention will be described with reference to the accompanying drawings. The embodiments of the present invention may be modified into various forms, and the scope of the present invention should not be construed as being limited to the embodiments described in detail below. The present embodiments are provided to enable those skilled in the art to more fully understand the present invention. Therefore, the shapes and the like of the elements in the drawings can be exaggeratedly expressed to emphasize a clearer description. It should be noted that in the drawings, the same members are denoted by the same reference numerals. Further, detailed descriptions of well-known functions and configurations that may be unnecessarily obscured by the gist of the present invention are omitted.

FIG. 1 is a perspective view showing an electric actuator using a DC motor according to the present invention, and FIG. 2 is a perspective view showing a disassembled state of the electric actuator of FIG. 1 and 2, an electric actuator according to an embodiment of the present invention includes a power input unit 100 including a motor, and a planetary gear that receives torque from the power input unit 100 to increase torque A speed increasing portion 300 having a plurality of teeth so as to adjust the speed of rotation reduced in proportion to a torque increased in the planetary deceleration portion 200 to a required speed, And a cylinder part 400 for converting the rotational motion transmitted to the linear motion. The speed increasing portion 300 may be provided with a removable cover 310 which is opened at one side so that the teeth of the speed increasing portion 300 can be replaced for adjusting the speed and torque of the linear movement of the cylinder portion 400 .

The power input unit 100 and the planetary deceleration unit 200 are coupled in a longitudinal direction extending in the axial direction (directions of arrows A and B), and the speed increasing unit 300 includes a planetary speed reducing unit 200, And is coupled to one end of a cylinder unit 400 installed substantially parallel to the input unit 100 and the planetary deceleration unit 200.

Since the power input unit 100 and the planetary reduction unit 200 are screwed to each other, the components can be replaced and shared, the shaft can be easily fitted, and the connection part is unnecessary. Easy maintenance is possible.
FIG. 3 is a cross-sectional view taken along the line CC of FIG. 1, and is a perspective view showing a state where the knuckle joint is disposed at an initial position, and FIG. 4 is a cross-sectional view taken along line CC of FIG. 1 and is a perspective view showing a knuckle joint protruding outward. 3 and 4, the cylinder 400 has a cylinder body 411 having an opening in a circular shape and passing through the cylinder body 400 in the axial direction (directions of arrows A and B), and the cylinder body 411 A displacement nut 410 which is rotatably coupled to the screw shaft 412 by screwing and which is vertically displaced; and a pair of guide grooves 410 and 420 formed on the outer circumferential surface of the displacement nut 410, And a knuckle joint 440 coupled to the other end of the displacement mechanism 420. The knuckle joint 440 has a cylindrical shape,

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The screw shaft 412 is longitudinally formed along the axial direction (the direction of the arrows A and B), and the outer peripheral surface of the screw shaft 412 is threaded. A first bearing 415 whose outer circumferential surface is in sliding contact with the inner surface of the displacement mechanism 420 is mounted on one end (direction A) of the screw shaft 412, and the other end (direction B) Is supported by the second bearing (414) mounted thereon, so that stable rotation within the cylinder body (411) is possible.

The displacement nut 410 is rotatably screwed to the screw shaft 412 and moves in the axial direction AB by the rotation of the screw shaft 412. The displacement nut 410 is provided at one side with the inner diameter of the cylinder body 411 A guide ring 413 having a predetermined diameter is engaged and slidably contacts within the cylinder body 411 to prevent vibration or departure. This rotation of the screw shaft 412 enables axial displacement of the displacement mechanism 420 coupled to the displacement nut 410.

The cylinder 400 is provided with a front cover 430 covering the opening surface of the cylinder body 411. The inside of the cylinder 430 is penetrated through the front cover 430 with the same diameter as the displacement mechanism 420, The displacement mechanism 420 is inserted into the front cover 420. The front cover 430 is provided with a locking protrusion 431 on its lower surface and functions as a stopper capable of regulating the displacement along the axial direction of the guide ring 413 during the movement of the displacement nut 410.

The power input unit 100 may be a DC DC motor. In detail, a DC motor that is rotationally driven by a current supplied from a power source (not shown) can be made smaller than a conventional AC motor and can generate a higher torque than the initial AC motor at the same size, Lt; / RTI > Therefore, the power can be transmitted by only the battery without the need of a separate AC power source.

Also, in the case of an electric actuator of an industrial machine which must obtain a high torque, an actuator using an AC power source is mainly provided. However, since it is difficult to control the DC motor as compared with a DC motor, a separate inverter device must be provided. Can be solved.

Therefore, the power transmitted from the power input section 100 driven by the electric signal is transmitted to the planetary deceleration section 200 and the rotation speed shortened by the speed increasing section 300 after the torque is increased in the planetary deceleration section 200 It can be increased as needed. Thereafter, the cylinder unit 400 is provided with a displacement nut 410 which can be displaced under a given stroke by the driving force from the speed increasing unit 300, so that the driving force from the speed increasing unit 300 is transmitted to the displacement mechanism 420, As shown in Fig.

The planetary deceleration unit 200 transmits a high torque to the speed increasing unit 300 through the output shaft 210. In this case, the operation principle of the planetary deceleration unit 200 is known to those skilled in the art, Detailed implementation steps are omitted.

The speed increasing portion 300 is screwed to the lower end of the planetary speed reducing portion 200 and the cover 310 capable of opening and closing is screwed to the speed increasing portion 300.

The speed increasing portion 300 includes a drive pulley 320 coupled to the output shaft 210 of the planetary reduction portion 200, a driven pulley 330 coupled to the screw shaft 412 of the cylinder portion 400, And a timing belt 340 suspended between the driving pulley 320 and the driven pulley 330.

A plurality of gear teeth are provided on the outer circumferential surface of the driving pulley 320 and the driven pulley 330 and the gear teeth formed on the inner circumferential surface of the timing belt 340 are engaged with gear teeth of the driving pulley 320 and the driven pulley 330 Lt; / RTI > The rotational driving force of the output shaft 210 of the planetary reduction gear 200 is transmitted from the driving pulley 320 to the driven pulley 330 by the timing belt 340 to rotate the screw shaft 412 The displacement nut 410 screwed to the screw shaft 412 can be displaced along the axial direction (the direction of arrows A and B).

In this case, the diameter of the drive pulley 320 is set to be larger than that of the driven pulley 330 to compensate the rotational speed lowered to the high torque transmitted from the planetary decelerator 200, According to the present invention, the cover 310 can be detachably detachably attached to the speed increasing portion 300, so that the driving pulley 320 and the driven pulley 330 can be easily replaced with the required number of revolutions in accordance with a required rotational speed.

(Example)

The electric actuator using the direct current motor in the embodiment of the present invention is basically configured as described above. Next, the operation and the operation effect will be described. The state in which the displacement nut 410 shown in FIG. 3 is accommodated in the cylinder body 411 will be described as an initial position. In the initial position of the displacement nut 410, a current is supplied to the power input unit 100 from a power source (not shown), and a high voltage is applied to the planetary deceleration unit 200 engaged with the output shaft 110 of the power input unit 100 The driving pulley 320 of the speed increasing portion 300 engaged with the output shaft 210 is rotationally driven and the rotational driving force is transmitted to the driven pulley 330 by the timing belt 340. [

The screw nut 412 connected to the driven pulley 330 is rotated so that the displacement nut 410 together with the displacement mechanism 420 moves toward the other end of the cylinder 400 in the direction of arrow B Displacement.

At this time, since the screw shaft 412 is supported by the second bearing 414 at the lower end and the upper end is supported by the first bearing 415, the screw shaft 412 rotates smoothly and highly accurately, The nut 410 can be displaced along the axial direction.

The guide ring 413 is hooked by the locking protrusion 431 of the front cover 430 attached to the upper end of the cylinder 400 to restrict the displacement of the displacement nut 410. The front cover 430 The rotational displacement is restricted by the displacement mechanism 420 fitted in the inner hole of the cylinder body 411 and the guide ring 413 fitted in the cylinder body 411 so that the displacement nut 410 can be displaced only along the axial direction It is.

4, the displacement nut 410 and the displacement mechanism 420 are displaced upward so that the knuckle joint 440 is gradually protruded so as to be exposed to the outside of the cylinder 400. As shown in FIG.

When the front cover 430 is displaced to one end side (in the direction of arrow A) at a position displaced to the other end of the cylinder part 400, when the DC motor of the power input part 100 is rotated in the opposite direction, The driving pulley 320 and the driven pulley 330 of the planetary decelerator 200 and the speed increasing portion 300 are rotated in the opposite direction and the driving force of the displacement nut 410 Is displaced toward one end side (direction A) of the cylinder part 400, so that the displacement mechanism 420 is slowly accommodated in the inward direction. Thus, the knuckle joint 440 returns to its initial position.

Therefore, the electric actuator using the direct current motor according to the present invention is configured to increase the torque as much as possible by using the planetary deceleration unit 200 and then increase the speed to the required speed in the speed increasing unit 300. The planetary deceleration unit 200 is designed separately The power input unit 100 can be efficiently used as compared with the AC motor when the DC motor is used to move a structure having a large initial frictional force.

The embodiments of the electric actuator using the direct current motor of the present invention described above are merely illustrative and those skilled in the art will appreciate that various modifications and equivalent embodiments are possible without departing from the scope of the present invention. . Therefore, it is to be understood that the present invention is not limited to the above-described embodiments. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims. It is also to be understood that the invention includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

100: Power input section
110: Output shaft
200: planetary reduction part
210: Output shaft
300:
310: cover
320: Driving pulley
330: Follow pulley
340: timing belt
400:
410: Displacement nut
411: Cylinder body
412: Screw shaft
413: Guide ring
414: Second bearing
415: first bearing
420: Displacement mechanism
430: Front cover
431:
440: Knuckle joint

Claims

A power input unit 100 including a direct current DC motor;
A planetary reduction unit 200 including a planetary gear that receives a driving force from the power input unit 100 to increase a torque and includes an output shaft 210;
A speed increasing portion 300 having a detachable cover 310 to which a driving force is transmitted from the planetary deceleration portion 200 and is increased in speed in proportion to an increased torque and is opened at one side; And
And a cylinder part (400) having a screw shaft (412) in which a screw thread is formed to convert a rotational motion transmitted from the speed increasing part (300) into a linear motion,
The speed increasing unit 300 includes:
A driving pulley 320 coupled to the output shaft 210 of the planetary reduction unit 200, a driven pulley 330 coupled to the screw shaft 412 of the cylinder unit 400, And a timing belt (340) suspended between the frame (330)
The drive pulley 320 is larger in diameter than the driven pulley 330 and the drive pulley 320 and the driven pulley 330 can be attached to and detached from the cover 310 after opening and closing the cover 310,
The cylinder part (400)
The screw shaft 412 having a cylinder body 411 having a circular cross section opened in the axial direction and accommodated in the cylinder body 411 and having a thread formed on the outer circumferential surface thereof, A cylindrical displacement type displacement mechanism 420 having one end connected to the outer circumference of the displacement nut 410 and a displacement nut 420 coupled to the other end of the displacement mechanism 420, Knuckle joint 440,
The displacement nut 410 is received in the cylinder body 411 and has a guide ring 413 having a diameter corresponding to the inner diameter of the cylinder body 411 at one side,
A first bearing 415 is mounted on one end of the screw shaft 412 and an outer circumferential surface thereof is in sliding contact with the inner surface of the displacement mechanism 420. The other end of the screw shaft 412 is inserted into the cylinder body 411 Is supported by a second bearing (414) mounted on the speed increasing portion (300) so as to enable stable rotation of the motor (100).

The method according to claim 1,
The power input unit 100 and the planetary reduction unit 200 are coupled to each other in the longitudinal direction extending along the axial direction,
The cylinder part 400 is installed in parallel with the power input part 100 and the planetary reduction part 200,
Wherein the speed increasing portion 300 is coupled to the planetary reduction portion 200 at one side and to one end portion of the cylinder portion 400 at the other side.

The method according to claim 1,
The drive pulley 320 and the driven pulley 330 are provided with a plurality of gear teeth on the outer circumferential surface thereof,
The timing belt 340 has gear teeth formed on its inner circumferential surface and is engaged with gear teeth of the drive pulley 320 and the driven pulley 330,
The rotational driving force of the output shaft 210 of the planetary decelerator 200 is transmitted to the driving pulley 320 and is transmitted to the driven pulley 330 by the timing belt 340 to rotate the screw shaft 412 And displaces the displacement nut (410) screwed on the screw shaft (412) in the axial direction.

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The method according to claim 1,
The cylinder 400 includes a front cover 430 covering an upper opening surface of the cylinder body 411,
The inside of the front cover 430 penetrates through the same diameter as the displacement mechanism 420. The displacement mechanism 420 is inserted into the front cover 430,
And a locking protrusion 431 for restricting displacement of the guide ring 413 in the axial direction when the displacement nut 410 moves back and forth is provided on the lower surface of the front cover 430.