WO2022014749A1

WO2022014749A1 - Cycloid-type electric cylinder

Info

Publication number: WO2022014749A1
Application number: PCT/KR2020/009384
Authority: WO
Inventors: 오준민; 한재오; 신재원; 정원형; 이종석
Original assignee: 성일주식회사
Priority date: 2020-07-16
Filing date: 2020-07-16
Publication date: 2022-01-20

Abstract

The present invention relates to a cycloid-type electric cylinder, and the purpose of the present invention is to provide a cycloid-type electric cylinder that effectively reduces a thrust load transferred to a rotary shaft of a motor without using a thrust bearing. To this end, the present invention provides a cycloid-type electric cylinder comprising: a motor; an inner support supporting a rotary shaft of the motor; a cylinder housing which is fixed to the motor along with the inner support while accommodating the inner support therein; a piston rod which is installed such that a part thereof is inserted between the inner support and the cylinder housing, and which has a female screw portion formed in the inner circumferential surface thereof; a cycloid plate which is eccentrically coupled to the rotary shaft, has a plurality of pinholes formed to be distributed in the circumferential direction, and has an annular movable protrusion formed on the outer circumferential surface thereof to be inserted in a screw valley of the female screw portion so as to move the piston rod while revolving around the rotary shaft when the rotary shaft rotates; and a plurality of cycloid pins which pass through the pinholes and are installed on the inner support so as to pass through the pinholes at eccentric positions from the center of the pinholes, wherein load distribution inducing units each including one or more annular support protrusions are formed on the inner circumferential surface of the pinholes and the outer circumferential surface of the cycloid pins, the load distribution inducing units distributing the thrust load transferred to the cycloid plate while maintaining the engaged state and moving from each other on the basis of the lengthwise direction of the rotary shaft.

Description

Cycroid type electric cylinder

The present invention relates to an electric cylinder, and more particularly, two cycloid plates eccentrically coupled to the rotation shaft of the motor are made to push up or down the thread formed on the cylinder rod while revolving around the rotation shaft, and transmitted to the cycloid plate It relates to a cycloid-type electric cylinder that reduces the thrust load transmitted to the rotating shaft of the motor by dispersing the thrust load to the inner support through the cycloid pin.

In general, an electric cylinder is a cylinder configured to expand or contract while a piston rod moves back and forth by the operation of the motor, including a motor operated by electricity and a structure for converting rotational motion into linear motion.

Unlike a hydraulic cylinder or a pneumatic cylinder, the electric cylinder has a simple structure because it does not require a separate tank or a pump, and has the advantage that precise position control is possible.

Various methods are used for the electric cylinder, such as a method using a bolt and a nut, a ball screw method in which a plurality of balls are installed between the bolt and a nut, and a planetary screw method using a planetary screw.

The planetary screw method is useful where the cylinder thrust is high, but there is a problem in that a load is applied to the nut connected to the rotating shaft of the motor as it is, and a large burden is applied to the motor. can occur.

Accordingly, in designing an electric cylinder, various types of thrust bearings are applied in order to remove the thrust load acting on the motor through the rotating shaft, an example of which is disclosed in Patent Document 1.

However, since the thrust load transmitted to the motor through the rotating shaft cannot be completely removed only by applying the thrust bearing, it still imposes a great burden on the operation of the motor.

(Prior art literature)

(Patent Literature)

(Patent Document 1) Registered Patent Publication No. 10-1907397 (2018.10.12. Announcement)

The present invention has been made in consideration of the above problems, and an object of the present invention is to provide an electric cylinder of a cycloid type capable of effectively reducing a thrust load transmitted to a rotation shaft of a motor without applying a thrust bearing.

The present invention for achieving the object as described above and performing the task for eliminating the drawbacks of the prior art is a motor operated by electricity; an inner support fixed to the motor to support a portion of the rotation shaft extending from the motor while being accommodated therein; a cylinder housing fixedly installed to the motor together with the inner support while accommodating the inner support therein; a piston rod having a cylindrical structure, a part of which is inserted between the inner support and the cylinder housing and installed to move back and forth while being supported by the cylinder housing, the piston rod having a female threaded portion formed on its inner circumferential surface; It is eccentrically coupled to the rotating shaft, a plurality of pinholes are formed to be dispersed in the circumferential direction, and at least one annular movable protrusion inserted into the screw bone formed in the female screw portion is formed on the outer circumferential surface. one or more cycloid plates for moving the piston rod; and a plurality of cycloid pins installed on the inner support to pass through the pinhole, but penetrate the pinhole at an eccentric position away from the center of the pinhole to suppress the rotation of the cycloid plate and allow revolution. And on the outer peripheral surface of the cycloid pin, a load distribution inducing part composed of one or more annular support protrusions that disperses the thrust load transmitted to the cycloid plate to the inner support while maintaining the meshed state while displaced from each other based on the longitudinal direction of the rotation shaft is formed A cycloid type electric cylinder is provided.

On the other hand, in the electric cylinder of the cycloid type, the cycloid plate is made of two, and the two cycloid plates may be eccentrically installed on the rotational shaft to have a phase difference of 180 degrees.

Meanwhile, in the electric cylinder of the cycloid type, the annular movable protrusion may be formed to have a structure extending in a horizontal posture along the circumferential direction of the cycloid plate.

On the other hand, in the cycloid type electric cylinder, the load distribution induction part has a structure that protrudes from the inner circumferential surface of the pinhole, extends in a horizontal posture along the circumferential direction of the pinhole, and is formed to be dispersed in the height direction of the pinhole. a first annular support protrusion; And it is inserted between the first annular support protrusions and protrudes from the outer circumferential surface of the cycloid pin to be coupled with the first annular support protrusion, and has a structure extending in a horizontal posture along the circumferential direction of the cycloid pin, It may be composed of; a plurality of second annular support protrusions formed to be dispersed in the height direction.

On the other hand, in the electric cylinder of the cycloid type, the guide rail is formed to protrude from the inner peripheral surface of the cylinder housing to have a structure extending along the longitudinal direction of the cylinder housing; and a guide groove formed on the outer circumferential surface of the piston rod to move along the guide rail while being coupled to the guide rail to suppress rotation of the piston rod and allow forward and backward movement.

According to the present invention having the above characteristics, when the piston rod is operated, the thrust load transmitted to the cycloid plate through the piston rod is distributed to the inner support through the cycloid pin. Thrust load can be significantly reduced.

1 is an internal configuration diagram of a cycloid type electric cylinder according to a preferred embodiment of the present invention;

Figure 2 is a perspective view showing a part of the electric cylinder of the cycloid type in accordance with a preferred embodiment of the present invention,

3 is a detailed view of a main operating part of a cycloid type electric cylinder according to a preferred embodiment of the present invention;

4 is a perspective view showing the structure of first and second cycloid plates and cycloid pins according to the present invention;

5 is a cross-sectional view showing a state in which the cylinder housing and the piston rod according to the present invention are coupled by a guide rail and a guide groove;

6 is an exemplary view showing a state in which the cycloid plate according to the present invention revolves inside the piston rod.

(Explanation of symbols)

(Explanation of symbols for main parts of the drawing)

110: motor 111: rotation shaft

120: inner support 130: cylinder housing

131: guide rail 140: piston rod

141: guide groove 142: female thread part

150: cycloid plate 152: pinhole

153: annular movable projection 160: cycloid pin

170: load distribution induction part 171: first annular support protrusion

172: second annular support projection

Hereinafter, preferred embodiments of the present invention will be described in detail in conjunction with the accompanying drawings. In describing the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

Figure 1 is an internal configuration diagram of a cycloid-type electric cylinder according to a preferred embodiment of the present invention, Figure 2 is a perspective view showing a part of the cycloid-type electric cylinder according to a preferred embodiment of the present invention, 3 is a detailed view of the main operating part of a cycloid type electric cylinder according to a preferred embodiment of the present invention, and FIG. 4 is a perspective view showing the structure of the first and second cycloid plates and cycloid pins according to the present invention , Figure 5 is a cross-sectional view showing a state in which the cylinder housing and the piston rod according to the present invention are coupled by a guide rail and a guide groove, Figure 6 is an example showing a state in which the cycloid plate according to the present invention revolves inside the piston rod shows the diagram.

The cycloid-type electric cylinder according to the present invention is composed of a motor 110 , an inner support 120 , a cylinder housing 130 , a piston rod 140 , a cycloid plate 150 , and a cycloid pin 160 , , is made to move the piston rod 140 while the cycloid plate 150 revolves around the rotation shaft 111 of the motor 110 by the operation of the motor 110 .

The motor 110 may be made of a known motor including a stator and a rotor, and is configured to rotate the rotating shaft 111 while operating by electricity.

On the other hand, the rotation shaft 111 has a structure that extends from the motor 110 through the inner support 120 to protrude into the inside of the cylinder housing 130, and the inner support 120 through the bearing B1. It is coupled to and rotated by the operation of the motor 110 while being supported by the inner support 120 .

In addition, the rotating shaft 111 includes one or more eccentric parts 112 to which the cycloid plate 150 is coupled, and the eccentric part 112 has an eccentric structure whose center is deviated from the center of the rotating shaft 111 . formed to have

A bearing B2 for reducing frictional resistance generated between the cycloid plate 150 and the eccentric portion 112 is installed on the eccentric portion 112 of the rotation shaft 111 .

Meanwhile, the rotating shaft 111 according to the preferred embodiment of the present invention includes two eccentric parts 112 , and the two eccentric parts 112 are formed to have a phase difference of 180 degrees.

The inner support 120 supports the rotation shaft 111 and the cycloid pin 160 , and has a cylindrical structure elongated along the rotation shaft 111 , and has one end fixed to the motor 110 . do.

This inner support 120 is located inside the piston rod 140, the outer peripheral surface is formed to be spaced apart from the inner peripheral surface of the piston rod 140 is formed so as not to interfere with the forward and backward movement of the piston rod (140).

The cylinder housing 130 is to support the forward and backward movement of the piston rod 140, is disposed on the outside of the piston rod 140 to surround the circumference of the piston rod 140, together with the inner support 120, the motor ( 110) is configured to be fixed.

The cylinder housing 130 may be fixed to the motor 110 together with the inner support 120 by a bolt that passes through the inner support 120 and is fastened to the motor 110 .

On the other hand, a guide rail 131 is formed on the inner peripheral surface of the cylinder housing 130 , and a guide groove 141 is formed on the outer peripheral surface of the piston rod 140 , and the guide rail 131 and the guide groove 141 are combined. By this, the piston rod 140 can only move back and forth while the rotation is suppressed.

More specifically, the guide rail 131 is formed to protrude from the inner circumferential surface of the cylinder housing 130 and to extend long in the longitudinal direction of the cylinder housing 130 .

A plurality of such guide rails 131 may be formed to be dispersed in the circumferential direction of the cylinder housing 130 .

The guide groove 141 is processed to have a certain depth from the outer circumferential surface of the piston rod 140 so as to be coupled with the guide rail 131 in such a way that a part of the guide rail 131 is inserted therein, the piston rod 140 ) is formed on the outer peripheral surface of the piston rod 140 to maintain a state coupled to the guide rail 131 in the process of moving back and forth.

A plurality of such guide grooves 141 may be formed to be dispersed in the circumferential direction of the piston rod 140 in correspondence to the guide rails 131 .

The piston rod 140 has a cylindrical structure, and a part is inserted between the inner support 120 and the cylinder housing 130 and is installed to move in the front-rear direction while being supported by the cylinder housing 130 .

A female screw part 142 that forms a thrust together with the cycloid plate 150 is formed on the inner circumferential surface of the piston rod 140, and the female screw part 142 is a single-row screw or a multi-line screw consisting of two or more threads. can be

On the other hand, the female screw portion 142 according to the preferred embodiment of the present invention is made of a two-line screw.

The cycloid plate 150 moves the piston rod 140 while revolving around the rotation shaft 111 when the rotation shaft 111 rotates, and is made of a circular plate material having a predetermined thickness, and the rotation shaft 111 ), the shaft coupling hole 151 to which the eccentric part 112 is coupled is formed in the center, and a plurality of pinholes 152 are formed to have a circular arrangement structure around the shaft coupling hole 151, and the piston rod ( An annular movable protrusion 153 coupled to the female screw portion 142 of 140 to move the piston rod 140 is formed on the outer circumferential surface.

On the other hand, the annular movable protrusion 153 may be formed in various cross-sections such as a triangle, a square, a circle, an oval, etc., and protrude from the outer circumferential surface of the cycloid plate 150 , along the circumferential direction of the cycloid plate 150 . It is formed to have a structure extending in a horizontal position, and a plurality of them may be formed to be dispersed in the height direction of the cycloid plate 150, and in FIG. The structure forming the form is shown.

One or more such cycloid plate 150 may be installed on the rotation shaft 111, and the cycloid type electric cylinder according to the preferred embodiment of the present invention has two cycloid plates 150 having a phase difference of 180 degrees. consists of including

The cycloid pin 160 is to appropriately limit the movement of the cycloid plate 150 to induce the cycloid plate 150 to revolve while the rotation is suppressed, and a pinhole formed in the cycloid plate 150 . It passes through 152, but is arranged to pass through the pinhole 152 at an eccentric position away from the center of the pinhole 152, and a part passes through the cycloid pin 160 to the bolt fastened to the inner support 120. It is made to be fixed to the inner support 120 by the.

As such, it is preferable that the cycloid pin 160 installed on the inner support 120 via the bolt is installed to enable free rotation around the bolt.

On the other hand, the cycloid pin 160 is formed in plurality so that one cycloid pin 160 can each pass through the plurality of pinholes 152 formed in the cycloid plate 150 .

In the cycloid type electric cylinder configured as described above, the load distribution inducing part 170 for dispersing the thrust load transmitted to the cycloid plate 150 to the inner support 120 is a pinhole 152 and a cycloid pin 160 ) is composed of

The load distribution inducing unit 170 includes a plurality of first annular support protrusions 171 formed on the inner circumferential surface of the pinhole 152 and a plurality of second annular support protrusions 172 formed on the outer circumferential surface of the cycloid pin 160 . and the first annular support protrusion 171 and the second annular support protrusion 172 are configured to maintain an engaged state while shifted from each other in the longitudinal direction of the rotation shaft 111 .

That is, the first annular support protrusion 171 is formed to protrude from the inner circumferential surface of the pinhole 140 , and is formed to have a structure extending in a horizontal posture along the circumferential direction of the pinhole 152 .

The first annular support protrusion 171 has a polygonal cross section, such as a triangle or a quadrangle, and a plurality of them may be formed to be dispersed in the height direction of the pinhole 152, and in FIG. 3, a plurality of first The structure in which the annular support protrusions 171 are dispersed to form a structure continuously connected along the height direction of the pinhole 152 is shown.

The second annular support protrusion 172 is formed to protrude from the outer circumferential surface of the cycloid pin 160 so as to be inserted between the first annular support protrusions 171 , and the circumferential direction of the cycloid pin 160 . It is formed to have a structure extending in a horizontal posture along the

The second annular support protrusion 172 has a polygonal cross section such as a triangle or a quadrangle, and a plurality of them may be formed to be dispersed in the height direction of the cycloid pin 160, and in FIG. The structure in which the second annular support protrusion 172 is dispersed to form a structure continuously connected along the height direction of the cycloid fin 160 is shown.

Hereinafter, the operation of the cycloid-type electric cylinder according to the present invention will be described in detail, and through this, the operational effect of the cycloid-type electric cylinder according to the present invention will be clearly shown.

The electric cylinder of the cycloid type according to the present invention is operated by driving the motor 110 .

That is, when the rotation shaft 111 rotates due to the driving of the motor 110 , the cycloid plate 150 installed on the eccentric part 112 of the rotation shaft 111 moves in response to a change in the position of the eccentric part 112 . while revolving around the rotating shaft 111 .

On the other hand, the cycloid pin 160 installed to penetrate the pinhole 152 of the cycloid plate 150 while being coupled to the inner support 120 suppresses the cycloid plate 150 from rotating together with the rotation shaft 111 . In the end, the cycloid plate 150 revolves while its rotation is suppressed.

As such, in the process of the cycloid plate 150 revolving, the annular movable protrusion 153 formed on the outer circumferential surface of the cycloid plate 150 is partially engaged with the female threaded portion 142 of the piston rod 140 is maintained. , since the engagement position of the female screw part 142 and the annular movable protrusion 153 continuously changes in the clockwise or counterclockwise direction by the revolution of the cycloid plate 150, in the direction in which the cycloid plate 150 revolves. Accordingly, since the annular movable protrusion 153 pushes up or down the threads constituting the female screw portion 142 , a forward operation or a backward operation of the piston rod 140 is implemented.

On the other hand, the position of the cycloid pin 160 installed to penetrate the pinhole 152 of the cycloid plate 150 is continuously changed in the pinhole 152 due to the revolution of the cycloid plate 150, but the pinhole ( A portion of the first annular support protrusion 171 formed on 152 and the second annular support protrusion 172 formed on the cycloid pin 160 is always maintained in an engaged state regardless of the position of the cycloid pin 160. .

Accordingly, the thrust load transmitted from the piston rod 140 to the cycloid plate 150 in the course of the movement of the piston rod 140 is through the first annular support protrusion 171 and the second annular support protrusion 172 . Since the thrust load transmitted to the cycloid pin 160 and transmitted to the cycloid pin 160 is transmitted and distributed to the inner support 120, the thrust load transmitted from the cycloid plate 150 to the rotation shaft 111 is reduced. can be significantly reduced.

Therefore, in the cycloid type electric cylinder according to the present invention, the use of a thrust bearing is not required at all.

As described above, the cycloid-type electric cylinder according to the present invention has a very simple structure, so it is easy to manufacture and maintain, and the motor 110 through the rotating shaft 111 without the use of a thrust bearing. This is a very useful invention that can prevent damage to the motor 110 by remarkably reducing the thrust load transmitted to the motor.

The present invention is not limited to the specific preferred embodiments described above, and various modifications are possible by anyone with ordinary skill in the art to which the invention pertains without departing from the gist of the invention as claimed in the claims. Of course, such modifications are intended to be within the scope of the claims.

Claims

a motor 110 operated by electricity;

an inner support 120 fixedly installed to the motor 110 to support a portion of the rotation shaft 111 extending from the motor 110 while being accommodated therein;

a cylinder housing 130 fixedly installed to the motor 110 together with the inner support 120 while accommodating the inner support 120 therein;

It is made of a cylindrical structure, and a part is inserted between the inner support 120 and the cylinder housing 130 and is installed to move forward and backward while being supported by the cylinder housing 130, and a female screw part 142 is formed on the inner circumferential surface. a piston rod 140 made of;

It is eccentrically coupled to the rotation shaft 111, a plurality of pinholes 152 are formed to be dispersed in the circumferential direction, and at least one annular movable protrusion 153 inserted into the screw bone formed in the female screw portion 142 is formed on the outer circumferential surface. one or more cycloid plates 150 for moving the piston rod 140 while revolving around the rotating shaft 111 when the rotating shaft 111 rotates; and

It is installed in the inner support 120 to penetrate the pinhole 152, but to penetrate the pinhole 152 at an eccentric position away from the center of the pinhole 152 to suppress the rotation of the cycloid plate 150 and allow revolution. Consists of a plurality of cycloid pins (160);

Inner support ( 120), a cycloid type electric cylinder, characterized in that the load distribution induction part 170 made of one or more annular support projections are formed.
The method according to claim 1,

The cycloid plate 150 is made of two, and the two cycloid plate 150 is a cycloid type electric cylinder, characterized in that it is installed eccentrically on the rotation shaft 111 so that the phase difference of 180 degrees.
The method according to claim 1,

The annular movable protrusion (153) is a cycloid type electric cylinder, characterized in that it is formed to have a structure extending in a horizontal posture along the circumferential direction of the cycloid plate (150).
The method according to claim 1,

The load distribution induction unit 170,

A plurality of first annular support protrusions 171 protruding from the inner circumferential surface of the pinhole 152 , having a structure extending in a horizontal posture along the circumferential direction of the pinhole 152 , and dispersed in the height direction of the pinhole 152 . ; and

It is inserted between the first annular support protrusions 171 and protrudes from the outer circumferential surface of the cycloid pin 160 so as to be coupled with the first annular support protrusion 171 , and is horizontal along the circumferential direction of the cycloid pin 160 . A cycloid type electric cylinder comprising; a plurality of second annular support protrusions 172 that have a structure extending in the posture and are formed to be dispersed in the height direction of the cycloid pin 160.
The method according to claim 1,

a guide rail 131 formed to protrude from the inner circumferential surface of the cylinder housing 130 to have a structure extending in the longitudinal direction of the cylinder housing 130; and

a guide groove 141 formed on the outer circumferential surface of the piston rod 140 to move along the guide rail 131 while being coupled to the guide rail 131 to suppress the rotation of the piston rod 140 and allow for forward and backward movement; A cycloid type electric cylinder further comprising a.