JP2020533545A - Cycloid reducer with backlash prevention function - Google Patents

Abstract

An object of the present invention is to design and configure an inner pin that meshes with the outer teeth of a cycloid rotor that rotates eccentrically in a housing, or a rotor pin that is arranged inside a through hole of the cycloid rotor into a cylindrical structure that can be elastically deformed. An object of the present invention is to provide a speed reducer capable of removing (preventing) backlash between members. The present invention relates to a cycloid reducer having a backlash prevention function, and is inserted into through holes of one or more cycloid rotors eccentrically rotatably stacked on the outer peripheral surface of the input shaft to apply output torque to the output shaft. Backlash can be removed (prevented) by means of an elastically deformable rotor pin that transmits and an elastically deformable inner pin that meshes with the tooth profile of one or more cycloid rotors. Further, the present invention has a structure capable of applying a preload in the thrust direction by arranging a disc type bush on one or more cycloid rotors arranged in the axial direction and arranging a disc spring on the output shaft. ..

Description

The present invention relates to a cycloid reducer having a backlash prevention function.

Industrial robots provide movement to joint structures with a large number of joint degrees of freedom through actuator motors, servomotors, and the like. For robot joints, a reduction gear is generally installed at the output stage of the servomotor in order to obtain high output torque from the servomotor or the like.

Industrial robots employ a harmonic drive system or a cycloidal drive system for deceleration. For example, in the cycloidal reducer of Patent Document 1, the outer teeth of the cycloid disk are output shafts. It is possible to transmit a large torque through a structure that decelerates the rotational force of the input shaft and transmits it to the output shaft by meshing with the internal teeth of the robot, and because the reduction ratio is large, the reduction gear in various fields. It is used as. However, as described in Patent Document 1, there is a problem that the position accuracy is limited due to noise, vibration and backlash due to the translational motion of the cycloid tooth profile gear.

Briefly, in Patent Document 1, one pair of a first cycloid disc and a second cycloid disc manufactured separately from each other are configured as a set in a state of facing each other, and a tooth profile formed on each disc. It is described that it works to reduce backlash by providing a small phase difference between.

However, the outer teeth of the first cycloid disc and the outer teeth of the second cycloid disc backlash on the back to assist the rotation of the gear in the process of partially meshing with the inner teeth of the output member. There is no choice but to provide (backlash).

Experts in the field place rollers on the outer peripheral surface of the cycloid disc that engage with the external teeth, but this also guarantees the rotation of the rollers without any extra space such as backlash. become unable.

Korean Registered Patent No. 10-14247939

The present invention has been made in view of the above prior art, and an object of the present invention is to be arranged inside an inner pin that meshes with the outer teeth of a cycloid rotor that rotates eccentrically in a housing, or a through hole of the cycloid rotor. It is an object of the present invention to provide a speed reducer capable of removing (preventing) backlash between constituent members by designing a rotor pin having a cylindrical structure that can be elastically deformed.

In order to achieve the above object, the cycloid speed reducer having the backlash prevention function according to the preferred embodiment of the present invention has a speed reduction unit that reduces the input torque and a speed reduction unit that transmits a preset reduction torque through the speed reduction unit to the outside. Equipped with an output unit that transmits output torque to
The deceleration section has an input shaft that transmits input torque, a hollow housing that can accommodate the input shaft, and a large number of through holes and edges that are evenly spaced in the internal region in the circumferential direction. One or more cycloid rotors that have tooth profiles formed along the lines and are eccentrically and rotatably stacked on the outer peripheral surface of the input shaft in contact with the tooth profiles of one or more cycloid rotors. A large number of elastically deformable inner pins arranged along the circumference of the inner peripheral surface of the housing and a large number of elastically deformable inner pins extending toward the rear stage in a large number of through holes arranged in the axial direction. It consists of a rotor pin and
The output unit is the front end side of the main body so as to accommodate the aerial main body, the aerial journal whose length is extended from the center of one surface of the main body to the rear end side, and one end of the elastically deformable rotor pin. It has accommodating grooves arranged at equal intervals in the circumferential direction, and is composed of an output shaft that transmits output torque to the outside and an aerial housing cover that can accommodate the output shaft.

In embodiments of the present invention, the elastically deformable inner pin can provide preload to the cycloid rotor tooth process during eccentric rotation to prevent backlash between the inner pin and the cycloid rotor tooth process. The elastically deformable rotor pin provides preload to the through hole of the cycloid rotor during eccentric rotation and backlashes between the rotor pin and the through hole of the cycloid rotor, while consisting of a cylindrical member with a hollow inside. It is made of a cylindrical member having a hollow portion inside so as to prevent the above.

Further, the present invention can additionally form a slot in the length direction from the lower end of the elastically deformable inner pin, and additionally form a slot in the length direction from the lower end of the elastically deformable rotor pin. be able to.

The present invention may additionally place a disc spring at the intersection of the body and the journal so that preload can be provided via elastic force to eliminate play (gap) with respect to the thrust load of the output shaft. it can.

The disc springs can be made of elastic material so that they can be selected.

Preferably, the aerial housing is an annular plate having a central hole in the center of the internal region that allows the input shaft to penetrate, a side wall formed along the periphery of the edge of the annular plate, and the edge of the central hole. It is possible to provide a step portion formed on the periphery and a housing groove arranged at equal intervals in the circumferential direction along the circumference of the inner peripheral surface in order to arrange the inner pin in the axial direction.

Preferably, the aerial housing cover has an annular plate with a central hole in the center of the internal area that allows the output shaft to penetrate, a side wall formed along the periphery of the edge of the annular plate, and the edge of the central hole. It is possible to provide a step portion formed around the housing.

In the present invention, since the frictional force is reduced between the rotor pin and the through hole of the cycloid rotor, a tube type bush can be arranged around the inner peripheral surface of the through hole.

Preferably, the present invention allows disc-type bushes to be interposed between one or more cycloid rotors and discs on the front and rear sides of one or more cycloid rotors stacked and arranged so as to be selectable. Additional mold bushes can be placed.

Here, the tube type bush and the disc type bush can be made of a synthetic resin having a low coefficient of friction.

The disc type bush can additionally form an insertion hole that allows the rotor pin to penetrate.

The features and advantages of the present invention will be further clarified in the following detailed description based on the accompanying drawings.

Prior to this, the terms and words used herein and within the scope of the claim shall not be construed in a normal and lexical sense, as the inventor describes his invention in the best possible way. In addition, it should be interpreted as a meaning and concept that is consistent with the technical idea of the present invention, based on the principle that the concept of terms can be properly defined.

As described above, according to the description of the present invention, the present invention removes backlash between the inner pin and / or the rotor pin in contact with the cycloid rotor during eccentric rotation of the cycloid rotor, and has excellent positioning accuracy and durability. The torque transmission capacity can be improved.

In particular, the present invention can be realized simply through elastic deformation of hollow inner pins and / or rotor pins in order to prevent backlash, without the need for separate components.

The present invention can provide a structure having a spring effect that eliminates play between components with respect to a load in the thrust direction and imparts preload. This has the advantage of being able to adopt low cost ball bearings instead of expensive roller bearings and can prevent low friction drive, noise and vibration through structural stabilization.

It is a perspective view which shows typically the cycloid reducer which has the backlash prevention function by the preferable embodiment of this invention. It is an exploded perspective view of the cycloid reducer having the backlash prevention function shown in FIG. 1 as seen from the rear stage side. It is an exploded perspective view of the cycloid reducer having the backlash prevention function shown in FIG. 1 as seen from the front stage side. It is sectional drawing of the cycloid reducer having the backlash prevention function cut out along the line AA of FIG. It is an exploded perspective view which shows typically the output part in the state which removed the housing cover so that the arrangement state of an output shaft can be confirmed. It is a top view which shows the reduction gear with the output part removed from the rear stage side so that the arrangement state of a cycloid rotor can be confirmed. As a plan view showing the coupling state of the two cycloid rotors arranged on the shaft of the input shaft so as to be confirmed, the disc-shaped bush and the housing were removed at the reduction section shown in FIG. As a side view in which the coupling state of the two cycloid rotors arranged on the shaft of the input shaft can be confirmed, it is a side view of the speed reduction portion shown in FIG. 7. It is an exploded perspective view which shows the main part of the deceleration part shown in FIG. 2 schematically. It is a drawing which illustrates various types of rotor pins. It is a drawing which illustrates various types of inner pins. It is a stress distribution diagram of the elastically deformable hollow rotor pin of this invention and the conventional solid type rotor pin.

Objectives, particular advantages and novel features of the invention will be further apparent from the following detailed description and embodiments associated with the accompanying drawings. In the present specification, when a reference code is added to a component of each drawing, only the same component has the same code as much as possible even if it is displayed on another drawing. It should be noted that. In explaining the present invention, if it is determined that a specific explanation for the related publicly known technology unnecessarily obscures the gist of the present invention, the detailed description thereof will be omitted. In the present specification, terms such as first and second are used to distinguish one component from other components, and the components are not limited by the above terms. In the accompanying drawings, some components are exaggerated, omitted, or outlined, and the size of each component does not completely reflect the actual size.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The cycloid reducer according to the preferred embodiment of the present invention can be expected to eliminate backlash and improve positioning accuracy and durability despite the eccentric rotational movement of the cycloid rotor, thereby reducing noise and vibration. It is characterized by being designed so that it can be used.

With reference to FIGS. 1 to 9, a cycloid reducer having a backlash prevention function according to a preferred embodiment of the present invention is schematically illustrated.

As is already widely known to experts in the field, industrial robots require a power generation motor and a speed reducer that reduces the input torque of the motor. The present invention proposes a speed reducer capable of not only reducing the input torque of a motor, for example, a servo motor, but also preventing (or reducing) backlash as described above. The speed reducer according to the present invention is not limited to the industrial articulated robot, and may be adopted in various industrial fields.

The cycloid reducer having the backlash prevention function according to the preferred embodiment of the present invention can transmit power between a drive device (not shown) and an output device (not shown) coupled along the axial direction. Can be combined. The drive device is arranged in the input stage on the front stage side of the speed reducer, and can rotationally drive the hollow input shaft of the speed reducer, which is the rear stage equipment, through the rotational force of the motor. The output device is arranged in the output stage on the rear side of the reducer, and the input torque of the motor of the drive unit is transmitted through the eccentric rotation of the cycloid rotor arranged in the reducer to transmit the preset deceleration torque. The output torque is transmitted to the outside. Here, the front stage side means an input stage in which the input torque of the drive device is supplied and the direction is set toward the hollow input shaft, and the corresponding rear stage side transmits the output torque to the outside. It means an output stage whose direction is set toward the hollow output shaft.

As described above, the cycloid reducer having the backlash prevention function according to the preferred embodiment of the present invention has a reduction unit 1 that reduces the input torque provided by a drive device such as a motor, and a reduction unit that reduces the input torque of the drive device. It is composed of an output unit 2 that transmits a preset deceleration torque through 1 and transmits an output torque to the outside, and the deceleration unit 1 and the output unit 2 are coupled along the axial direction. For example, in the present invention, the housing 12 of the deceleration unit 1 and the housing cover 22 of the output unit 2 can be integrally coupled along the axial direction by various coupling methods such as screw fastening.

The reduction unit 1 includes a hollow input shaft 11 for transmitting the input torque of the motor, an aerial housing 12 surrounding the input shaft 11, and one or more cycloid rotors coupled to the outer peripheral surface of the input shaft 11. A number of inner pins arranged along the circumference of the inner peripheral surface of the housing 12 so as to mesh with the cycloid rotor) (13, 14) and the tooth profile formed around the outer peripheral surface of the cycloid rotor (13, 14). (Inner pin) 15 and a rotor pin 16 arranged in the internal region of one or more cycloid rotors (13, 14) stacked in the axial direction and transmitting deceleration torque to the outside. ..

The housing 12 is formed in a hollow cylindrical shape or a cup shape with the rear stage side open, and is formed along an annular plate 121 having a central hole 123 in the center of the internal region and the periphery of the edge of the annular plate 121. It is composed of a side wall 122 and a side wall 122. The center hole 123 is formed in a size and shape capable of rotatably accommodating the front stage side of the hollow input shaft 11, but is formed between the center hole 123 of the housing 12 and the hollow input shaft 11. Bearing B1 can be interposed. Incidentally, in the housing 12, accommodating grooves 125 arranged at equal intervals in the circumferential direction are arranged along the circumference of the inner peripheral surface thereof, and the inner pins 15 are positioned along the axial direction in the accommodating grooves 125. Can be done.

The center hole 123 is formed in a size and shape that allows penetration on the front stage side of the hollow input shaft 11, but a step portion 124 is formed on the inner surface of the annular plate 121 adjacent to the edge of the center hole 123. doing. The stepped portion 124 helps the first bearing B1 to rest on the inner surface of the annular plate 121.

The cycloid rotors (13, 14) are arranged on one or more stepped surfaces (without reference numerals) formed on the outer peripheral surface of the input shaft 11, but preferably the central insertion hole (13, 14) of the cycloid rotor (13, 14). Second and third bearings (B2, B3) can be interposed between 131, 141) and the outer peripheral surface of the input shaft 11. The cycloid rotors (13, 14) could be stably supported on the stepped surface formed on the outer peripheral surface of the input shaft by means of bearings (B2, B3). Here, one or more stepped surfaces are formed on the outer peripheral surface of the hollow input shaft 11 as described above, but are eccentric with respect to the axis center thereof.

As shown, the cycloid rotor 13 is formed in a flat disc shape, but has a central insertion hole 131 that is fitted around the outer peripheral surface (specifically, the stepped surface) of the input shaft at the center of the internal region. , One or more through holes 136 arranged at equal intervals in the circumferential direction in the internal region, and tooth profiles 135 continuously arranged along the periphery of the edge thereof.

The cycloid rotor 14 has a flat disk shape and can be arranged parallel to the cycloid rotor 13 and arranged along the axial direction of the input shaft 11, but at the center of the internal region the outer peripheral surface of the input shaft (specifically). Is a central insertion hole 141 fitted around the step surface), one or more through holes 146 arranged at equal intervals in the circumferential direction in the internal region, and continuously arranged along the periphery of the edge thereof. The tooth profile protrusion 145 is provided. The cycloid rotor 14 can be formed in the same shape and / or the same size as the cycloid rotor 13.

As a reference, the cycloid rotors (13, 14) have curved rounding tooth projections (135, 145) to minimize friction during eccentric rotation of the cycloid rotor in the process of rolling contact with the inner pin 15.

In the present invention, in order to minimize the friction during eccentric rotation of the cycloid rotor, the inner pin 15 is arranged around the edge of the cycloid rotor (13, 14), and the inner pin 15 and the tooth profile of the cycloid rotor (135, Make 145) roll into contact.

The inner pin 15 is settled in the accommodating groove 125 formed along the circumference of the inner peripheral surface of the aerial housing 12, while being arranged around the inner peripheral surface of the edge on the rear side of the opening of the housing 12. It is covered with an annular cover 19 and fixed in position. The inner pin 15 is arranged so as to mesh with the tooth profile (135, 145) around the edge of the cycloid rotor (13, 14) as shown, while effectively supporting the thrust load on the input side. , The cycloid rotors (13, 14) can be supported to allow eccentric rotation.

As a special case, the inner pin 15 is a cylindrical member having a hollow portion 151 inside, and can be made of an elastically deformable material. That is, since the inner pin 15 has a cylindrical structure with an empty space, the inner pin is formed on the tooth profile of the cycloid rotor (13, 14) when it meshes with the tooth profile of the cycloid rotor (13, 14). The shape of the inner pin can be modified to correspond to the shape. This allows backlash between the inner pin 15 and the tooth profile (135, 145) of the cycloid rotor to be eliminated.

As described above, the speed reducing unit 1 generates a deceleration torque that decelerates the input torque and converts it into a high output torque, is connected to the motor, transmits the input torque, and transfers this to the output unit 2 again. Although the input shaft 11 for transmission is provided, one or more cycloid rotors (13, 14) can be arranged along the axial direction of the input shaft 11.

The speed reduction unit 1 has a structure capable of eccentrically rotating the cycloid rotors (13, 14) to reduce the rotation speed according to a predetermined reduction ratio. Normally, the cycloid rotor induces vibration while rotating eccentrically, but one or more rotors, preferably two cycloid rotors (13, 14), are axially oriented so as to suppress such vibration. Place in.

The cycloid rotors (13, 14) have a large number of rotor pins 16 extended toward the rear stage in the through holes (136, 146) which are spaced apart from each other in the circumferential direction at equal intervals in the inner region thereof. Insert and place. A large number of rotor pins 16 assist in positioning one or more cycloid rotors (13, 14) stacked in the axial direction, as shown, while being coupled to the accommodation groove 212 of the output shaft 21. .. The eccentric rotation of the cycloid rotors (13, 14) reduces the reduction ratio while forcibly rotating each rotor pin 16 arranged in the through holes (136, 146) arranged in a row in the axial direction in the cycloid rotation direction. The input torque of the input shaft is axially coupled to the output shaft and rotated so as to be transmitted to the output torque.

The through holes (136, 146) should have a diameter larger than the size of the rotor pin 16. The through holes (136, 146) would have to be formed in a size larger than the outer shape of the rotor pins 16 to ensure eccentric rotation of the cycloid rotors (13, 14). Through holes (136, 146) can be formed in hollow portions of circular cross section so that they can be selected. The through hole is formed in a shape corresponding to the cylindrical rotor pin 16, so that the rotor pin 16 can rotate while being in contact with the inner peripheral surface of the through hole (136, 146). Since the inner peripheral surface of the through hole and the outer peripheral surface of the cylindrical rotor pin are configured to correspond to each other, wear of the through hole and the rotor pin can be significantly reduced during rotation.

Further, in the present invention, the rotor pin 16 is formed of a cylindrical member having a hollow portion 161 (see FIG. 10) inside, but it can be preferably made of a material that can be elastically deformed. That is, since the rotor pin 16 has a cylindrical structure with an empty inside, the rotor pin penetrates while being in contact with the inner peripheral surface of the through hole (136, 146) during the eccentric rotation of the cycloid rotor. The shape of the rotor pin can be modified to correspond to the inner diameter shape of the holes (136, 146). This allows not only stress relaxation between the rotor pin 16 and the through hole (136, 146) of the cycloid rotor, but also backlash elimination. The deformed state of the rotor pin arranged in the through hole of the cycloid rotor will be described in more detail with reference to FIG.

By the way, in the present invention, in order to reduce the frictional force between the inner peripheral surface of the through hole (136, 146) of the cycloid rotor (13, 14) and the rotor pin 16 during eccentric rotation, the through hole (136, 146) A tube-shaped bush 17 is arranged around the inner peripheral surface of the tube. The tube-shaped bush 17 can be made of a synthetic resin having a low coefficient of friction, such as Teflon®. The tube type bush 17 not only enables rotation with a low coefficient of friction as described above, but also can reduce noise and vibration when the rotor pin and the through hole come into contact with each other.

In the present invention, the hollow input shaft 11 has a disc type bush 18 interposed between two cycloid rotors (13, 14) laminated and arranged in the axial direction. The disc-shaped bush 18 applies a preload in the thrust direction so that play (distance) can be removed between the two cycloid rotors (13, 14). Preferably, the disc-shaped bush 18 can be made of a synthetic resin having a low coefficient of friction, such as Teflon. The disc type bush 18 can be positioned and fixed on the cycloid rotor by various methods such as double-sided tape and an adhesive.

The disc type bush 18 is not arranged so as to be limited only to the cycloid rotors (13, 14), but is various so as to eliminate the play phenomenon with the adjacent constituent members and to be adjacent to each other in a low friction state. Can be placed in various parts. For example, the disc-shaped bush 18 is located on the front side of one or more stacked cycloid rotors, which is the contact site between the inner surface of the annular plate 121 of the housing 12 and the cycloid rotor 14, and on the housing cover 22. It can also be selectively placed on the rear side of one or more stacked cycloid rotors, which is the contact site between the inner surface of the annular plate 221 and the cycloidator 13.

To be selectable, the disc-shaped bush 18 has through holes (136, 146) to allow penetration of rotor pins 16 housed in through holes (136, 146) of two cycloid rotors (13, 14). The insertion hole 186 can also be formed so as to correspond to.

The output unit 2 includes a hollow output shaft 21 that transmits the torque transmitted from the cycloid rotors (13, 14) of the speed reduction unit 1 to the outside, an aerial housing cover 22 that surrounds the output shaft 21, and an output shaft 21. A fifth bearing B5 arranged around the outer peripheral surface of the output shaft 21, a sixth bearing B6 arranged around the outer peripheral surface of the journal 213 of the output shaft 21, and a sixth bearing B6 toward the housing cover 22. It is composed of a disc spring 23 that applies a preload in the axial direction.

The hollow output shaft 21 is a hollow or cylindrical body 211 and a hollow or cylindrical journal whose length is extended from the center of one surface of the main body 211 in the external direction (rear stage side). The journal) 213 and a large number of accommodating grooves 212 accommodating one end of the rotor pin 16 are provided on the other surface (front stage side) of the main body 211. A large number of accommodating grooves 212 may be spaced apart from each other in the circumferential direction at equal intervals on the other surface of the main body 211.

As described above, the housing cover 22 is a hollow cylindrical or cup-shaped component whose front stage side is opened so as to cover the rear stage side release portion of the housing 12 forming the accommodation space of the cycloid rotor, as described above. It is formed in a shape capable of accommodating 21. The housing cover 22 is composed of an annular plate 221 having a central hole 223 in the center of the internal region and a side wall 222 formed along the periphery of the edge of the annular plate 221. The center hole 223 is formed in a size and shape that allows penetration of the journal 213 of the hollow output shaft 21, but a step portion 224 is formed on the inner surface of the annular plate 221 adjacent to the edge of the center hole 223. There is. The step portion 224 helps the sixth bearing B6 to rest on the inner surface of the annular plate 221.

The sixth bearing B6 can employ a ball bearing to axially support the journal 213 of the output shaft 21, and is not limited to this, and can be replaced with various types of bearings. The output unit 2 is a main body of the output shaft 21 in order to remove play between the sixth bearing B6 and the annular plate 222, and more specifically, the stepped portion 224 of the annular plate due to the load in the thrust direction. A disc spring 23 is placed at the intersection of 211 and the journal. The disc spring 23 applies a preload to the sixth bearing B6 on the rear stage side, in other words, in the axial direction, and can prevent wear, noise, vibration, and the like when the output shaft 21 rotates. The disc spring 23 is formed in a ring shape as shown so that it can come into contact with the inner ring portion of the sixth bearing B6. The disc spring 23 can be made of, for example, a urethane material, a synthetic resin, or the like, and may be any material that has elastic force and can provide a spring effect.

FIG. 10 is a drawing illustrating various examples of elastically deformable rotor pins.

The rotor pin 16 is a cylindrical member having a hollow portion capable of providing an elastically deformable structure due to an external force applied to contact with a through hole (136, 146) during eccentric rotation of the cycloid rotor. The upper portion of the rotor pin 16 is axially coupled to the accommodating groove 212 of the output shaft 21, and the lower portion of the rotor pin 16 is arranged in the through hole (136, 146) of the cycloid rotor (13, 14) (FIG. See 4).

FIG. 10A illustrates a cylindrical rotor pin 16 having a hollow portion 161 inside and closing the upper portion, and elastic deformation can be easily provided when an external force is applied by the hollow portion 161.

FIG. 10B illustrates a cylindrical rotor pin 16'with a hollow portion 161 inside and a closed upper portion, and an additional slot 162 is provided in the longitudinal direction from the lower portion of the side surface. When an external force is applied, the rotor pin 16'allows elastic deformation more easily by the hollow portion 161.

FIG. 10C illustrates a tube-shaped rotor pin 16 ”with a hollow portion 161 inside, and when an external force is applied by the hollow portion 161, elastic deformation can be easily provided.

FIG. 10D is provided with a hollow portion 161 inside, and an additional slot 162 is provided from the lower portion of the side surface to the upper portion along the length direction. When an external force is applied, the rotor pin 16 ”is more easily elastically deformed by the hollow portion 161.

FIG. 11 is a drawing illustrating various examples of elastically deformable inner pins.

The inner pin 15 is a cylindrical member having a hollow portion capable of providing an elastically deformable structure due to an external force applied from contact with a tooth profile (135, 145) during eccentric rotation of the cycloid rotor. The upper portion of the inner pin 15 is fixed in position on the annular cover 19, and the lower portion of the inner pin 15 is arranged in the accommodating groove 125 formed on the inner peripheral surface of the housing 12 (see FIG. 2).

FIG. 11A illustrates a tube-shaped inner pin 15 having a hollow portion 151 inside, and when an external force is applied by the hollow portion 151, elastic deformation can be easily provided.

FIG. 11B is provided with a hollow portion 161 inside, and an additional slot 152 is provided from the lower end portion of the side surface to the upper portion along the length direction. When an external force is applied, the inner pin 15'allows elastic deformation more easily by the hollow portion 151.

FIG. 11C illustrates a cylindrical inner pin 15 ”with a hollow portion 151 inside and a closed upper portion, and elastic deformation can be easily provided when an external force is applied by the hollow portion 151. ..

FIG. 11D illustrates a cylindrical inner pin 15 ″ ″ with a hollow portion 151 inside and a closed upper portion, and an additional slot 152 is provided in the longitudinal direction from the lower portion of the side surface. When an external force is applied, the inner pin 15 ″ allows elastic deformation more easily by the hollow portion 151.

FIG. 12 shows the stress distribution according to the contact portion between the through hole (136, 146) of the cycloid rotor and the rotor pin, and FIG. 12 (a) shows the elastically deformable hollow type rotor of the present invention. It is a stress distribution of a pin, and FIG. 12B is a stress distribution diagram of a solid type rotor pin by the prior art. The next experiment was carried out with the tube-shaped bush removed on the inner peripheral surface of the through hole.

FIG. 12A shows a through hole (136, 136,) formed in two cycloid rotors in which hollow (empty) rotor pins that can be elastically deformed are laminated and arranged in the axial direction without play as described above. The stress distribution of the contact portion between the parts is illustrated under the state of being inserted in 146). As shown, the rotor pin 16 is elastically deformed into a shape that is identical to the contact inner peripheral surface of the through hole (136, 146), allowing the removal of backlash between the rotor pin and the through hole. Not only that, the stress can be dispersed to ensure smooth rotation between each other.

FIG. 12B shows a state in which solid (full-filled) rotor pins are inserted into through holes (136, 146) formed in two cycloid rotors stacked and arranged in the axial direction without play. The stress distribution of the contact part between parts is illustrated below (0.1 mm + error added). As shown, the rotor pins are arranged in a forced fit manner inside the through holes (136, 146) to achieve backlash removal between the rotor pins and the through holes, but stress concentration at the contact sites. There is a considerable frictional force, and the rotation between them is not smooth, so there is no choice but to cause noise and vibration.

By the way, the inner pin of the present invention also adopts a structure that can be elastically deformed so as to prevent backlash while engaging with the tooth profile of the cycloid rotor, and has a structure similar to the hollow rotor pin described above. Therefore, stress dispersion can be expected at the time of contact with the tooth profile.

The present invention has been described in detail throughout the embodiments, but this is for the purpose of specifically explaining the present invention, and the cycloroid speed reducer having the backlash prevention function according to the present invention is not limited thereto. It becomes clear that the modification or improvement is possible by a person (a person skilled in the art) who has ordinary knowledge in the field within the technical idea of the present invention.

All simple modifications and modifications of the present invention belong to the scope of the present invention, and the specific scope of protection of the present invention will be clarified by the appended claims.

Claims (7)

A cycloid reducer including a speed reducer 1 for decelerating an input torque and an output unit 2 for transmitting a preset deceleration torque and transmitting an output torque to the outside via the speed reducer 1.
A large number of elastically deformable rotor pins 16 extending from the inside of a large number of through holes (136, 146) arranged at equal intervals in the circumferential direction toward the rear stage side in the internal region of the cycloid rotor of the speed reduction unit 1. Consists of including
The rotor pin 16 includes a cylindrical member having a hollow portion 161 inside and elastically deformable, and the upper portion of the rotor pin 16 is axially coupled to the accommodating groove 212 of the output shaft 21 and the upper portion is closed. A cycloid reducer with a backlash prevention function, which is characterized by being used. A cycloid reducer including a speed reducer 1 for decelerating an input torque and an output unit 2 for transmitting a preset deceleration torque and transmitting an output torque to the outside via the speed reducer 1.
A large number of elastically deformable rotor pins 16 extending from the inside of a large number of through holes (136, 146) arranged at equal intervals in the circumferential direction toward the rear stage side in the internal region of the cycloid rotor of the speed reduction unit 1. Consists of including
The rotor pin 16 includes a cylindrical member having a hollow portion 161 inside and elastically deformable, and the rotor pin 16 is characterized in that a slot 162 is additionally formed in the longitudinal direction from the lower stage portion. Cycloid reducer with backlash prevention function. The reduction gear 1 further includes an input shaft 11 to which input torque is transmitted and a hollow housing 12 capable of accommodating the input shaft 11.
The cycloid rotor has tooth projections (135, 145) formed along the periphery of the edge, and is characterized in that the cycloid rotor is eccentrically rotatably laminated in the axial direction on the outer peripheral surface of the input shaft 11. The cycloid reducer having a backlash prevention function according to claim 1 or 2. The speed reducer 1 further includes a number of inner pins 15 arranged along the periphery of the inner peripheral surface of the housing 12 so as to be in contact with the tooth profile (135, 145) of the cycloid rotor.
The cycloid reducer having a backlash prevention function according to claim 3, wherein the inner pin 15 is elastically deformable and includes a cylindrical member having a hollow portion 151 inside. The output unit 2 accommodates a hollow main body 211, a hollow journal 213 whose length is extended from the central portion of one surface of the main body 211 to the rear stage side, and one end of the rotor pin 16. The main body 211 is provided with accommodating grooves 212 arranged at equal intervals in the circumferential direction on the front stage side.
The first or second aspect of the present invention, wherein the output shaft 21 for transmitting the output torque to the outside and a hollow housing cover 22 capable of accommodating the output shaft 21 are included. Cycloid reducer with backlash prevention function. The cycloid reducer having a backlash prevention function according to claim 1 or 2, wherein the cycloid rotor has a tube type bush 17 arranged around an inner peripheral surface of the through hole (136, 146). The cycloid reducer having a backlash prevention function according to claim 6, wherein the tube bush 17 can be made of a synthetic resin having a low friction coefficient.