JP2021169862A - Rotation deceleration transmission device - Google Patents

Abstract

To reduce a manufacturing cost, to improve durability and reliability, to achieve size reduction, and to improve rotation transmission efficiency.SOLUTION: A rotation deceleration transmission device comprises: an oval shaft part 3 in which rolling bodies 3bm ... are interposed between a cam main body part 3c integrated with a rotation input part 2, and an inner ring 3bi and a flexible outer ring 3bo which are arranged at an external periphery of the cam main body part; an internal gear part 5 forming an inner gear 5g at an internal periphery; a flexible gear part 4 having an outer gear 4g which is reduced in the number of teeth with respect to the inner gear 5g, and engaged with the inner gear 5g in a plurality of engagement positions T ... when attached to an external periphery of the oval shaft 3, and having a plurality of transmission pin parts 4p ... ; and a rotation output mechanism 6 having an output plate part 7 having engagement holes 7sh ... with which the transmission pin parts 4p ... are engaged, and in which engagement parts 7s ... which are formed with every prescribed interval are formed in a peripheral direction Ff, and which permit the displacement of the transmission pin parts 4p ... to the peripheral direction Ff and/or a radial direction Fd at the transmission of rotation.SELECTED DRAWING: Figure 1

Description

The present invention relates to a rotation deceleration transmission device that decelerates and outputs a rotational movement to be input by incorporating it into a robot or the like.

Generally, in a production line of a production factory where mass productivity is required, an industrial robot configured by connecting a plurality of arm portions by a joint mechanism is installed. The joint mechanism rotatably connects the end of an arbitrary arm and the end of another arm, and reduces the rotation of the drive motor built into the arbitrary arm to about 1/100 to 1/200. It is equipped with a rotation deceleration transmission device that can decelerate and drive other arms to rotate by the decelerated rotation output. Therefore, this type of rotation deceleration transmission device is required to have high-precision positioning control, angle control, speed control, and the like.

Conventionally, as a rotation deceleration transmission device that meets such a demand, a speed reducer using a wave gear mechanism commonly known as a harmonic drive (registered trademark) has been widely used, and as a robot or a robot-related device equipped with this wave gear mechanism. For example, a prime mover disclosed in Patent Document 1, a wrist mechanism of an industrial robot disclosed in Patent Document 2, an articulated robot disclosed in Patent Document 3, and the like are known.

In this case, the prime mover disclosed in Patent Document 1 has a cup-shaped housing and a ring-shaped circular spline rotatably supported on the inner circumference of the housing, and is arranged inside the circular spline. , A harmonic speed reducer that is urged by a wave generator and fixes a cup-shaped flex spline that meshes with a circular spline to the housing, and one end of the support shaft is fixed to the housing and rotates around this support shaft. The casing is arranged inside the flexspline, and the casing is provided with a hydraulic motor provided with a wave generator so that the rotational output can be taken out from the circular spline.

Further, the wrist mechanism of the industrial robot disclosed in Patent Document 2 is supported by a third axis that rotates the entire wrist rotatably supported around the arm shaft supported by the arm and the third axis. , The second axis that tilts the tip of the wrist that is rotatably supported around the axis perpendicular to the third axis, and the second axis that is supported by the second axis and is rotatably supported around the axis perpendicular to the second axis. A first axis for rotating the processing tool grip portion at the tip of the wrist is provided, and the first axis and the second axis are decelerated in the wrist by a speed reducer arranged so as to overlap the same central axis, and the third axis is used. The shaft is configured to decelerate in advance outside the wrist.

Further, the articulated robot disclosed in Patent Document 3 is an articulated robot having at least two control arms and two speed reducers facing each other on the same axis provided at the joints of both control arms. Two speed reducers are attached to a common circular spline fixed to the joint of one control arm and one end of the common circular spline so as to rotate relative to the circular spline, and the other control arm. It is composed of first and second harmonic drive reduction shores equipped with brackets connected to the joints of the above.

Japanese Unexamined Patent Publication No. 60-098246 Japanese Unexamined Patent Publication No. 61-146490 Japanese Unexamined Patent Publication No. 64-01177

However, the conventional rotary deceleration transmission device provided with the wave gear mechanism described above has the following problems.

First, the main components are a flexspline, a wave generator, and a circular spline. The flexspline is formed entirely by a thin metal elastic plate into a cup shape, and the outer circumference of the opening that deforms into an ellipse. The gear portion formed in 1 is meshed with the gear portion formed on the inner circumference of the circular spline whose position is fixed. Therefore, since the flexspline integrally formed in a cup shape needs to be manufactured as a highly precise part, it is not easy to manufacture and cost increase is unavoidable. Moreover, the flexspline is liable to cause metal fatigue and malfunction due to use, and has difficulty in durability. After all, the conventional wave gear mechanism causes a significant increase in both initial cost and running cost.

Secondly, a gear part is formed on the outer circumference of the opening in the flexspline formed in a cup shape, and this gear part is wave-deformed by an elliptical wave generator, and a deceleration rotation is output to the center of the bottom part. In order to connect the shafts, in order for the flexspline to function, it is necessary to secure a certain amount of axial length of the flexspline, and there is a limit to reducing the overall structure (miniaturization) of the deceleration transmission device. there were

Thirdly, since the entire shape of the flexspline is formed in a cup shape and the output shaft is connected to the center of the bottom that closes one end, it is not easy to secure a space for routing the connection cable. In particular, in the case of a robot, since it has a large number of joint mechanisms and incorporates a large number of drive motors for realizing various movements, the number of connection cables connecting this drive motor and the robot controller is at least as many as the number of drive motors. As it becomes necessary, it is necessary to route a connection cable having this number. Therefore, there is room for further improvement from the viewpoint of securing a space in which a large number of connection cables can be routed.

An object of the present invention is to provide a rotation deceleration transmission device that solves the problems existing in such a background technique.

The rotation deceleration transmission device 1 according to the present invention is a rotation deceleration transmission device that decelerates and outputs the input rotational movement in order to solve the above-mentioned problems, and the rotation input unit 2 to which the rotational movement is input and the rotation thereof. A cam main body 3c that rotates integrally with the input portion 2, and an oval shaft portion 3 having a plurality of rolling elements 3bm interposed between an inner ring 3bi provided along the outer circumference of the cam main body 3c and a flexible outer ring 3bo. , The inner gear 5g is formed on the inner circumference and the position is fixed, and the internal gear portion 5 is formed along the circumferential direction Ff of the outer circumference, and the number of teeth is smaller than that of the inner gear 5g. A plurality of transmission pins having an outer gear 4g that meshes with the inner gear 5g at a plurality of meshing positions T ... in the circumferential direction Ff when attached to the outer periphery, and a plurality of transmission pins protruding from the side surface and provided at predetermined intervals along the circumferential direction Ff. The flex gear portion 4 having the portions 4p ... is engaged with each transmission pin portion 4p ... and is provided at predetermined intervals along the circumferential direction Ff. Alternatively, it is provided with a rotary output mechanism 6 having an output plate portion 7 provided with an engaging portion 7s ... forming an engaging hole 7sh ... that allows displacement in the radial direction Fd, and the engaging portion 7s ... is provided with the output plate portion. By forming it in 7, the peripheral surface of the transmission pin portion 4p ... Is always in contact with the output plate portion 7, and the transmission pin portion 4p ... It is characterized in that it is composed of a common hole 7sm.

In this case, according to a preferred embodiment of the invention, the center position of the transmission pin portion 4p ... Is rotatably supported around the transmission pin body 4pm ... Protruding from the flex gear portion 4 and the transmission pin body 4pm ... The output plate portion 7 can be formed in a ring shape while being configured by the transmission roller 4pr. Further, the rotation input portion 2 is a tubular shape formed in the wiring space S of cables Ka, Kb ... Inside the inner peripheral surface 11i, and at least the cam main body portion 3c of the oval shaft portion 3 is provided on the outer peripheral surface 11o. It can be configured by the input rotating body 11 of. Further, the flex gear portion 4 can be meshed at two meshing positions T and T having a positional relationship of 180 [°] with respect to the inner gear 5g of the internal gear portion 5.

According to the rotation deceleration transmission device 1 according to the present invention having such a configuration, the following remarkable effects are obtained.

(1) Since the conventional flexspline that forms the entire shape into a cup shape using a thin metal elastic plate material becomes unnecessary, it can be easily manufactured, the manufacturing cost can be significantly reduced, and metal fatigue and operation can be achieved. Since defects and the like can be significantly reduced, durability and reliability can be improved, and a significant cost reduction in both initial cost and running cost can be realized.

(2) Since the conventional flexspline is not required, the size of the arrangement space in the axial direction Fs can be reduced. Therefore, the overall structure can be made thinner, and further miniaturization of industrial robots and the like, which has a limit in miniaturization, can be easily realized.

(3) When the engaging portion 7s ... Is formed, it is formed on the output plate portion 7, and the peripheral surface of the transmission pin portion 4p ... Since it is composed of the bidirectional engaging holes 7sm ... that allow the displacement of the transmission pin portion 4p ..., the circumferential direction Ff and the radial direction Fd of the transmission pin portion 4p ... with respect to the engaging holes 7sh ... The displacement can be absorbed by the cam method, so to speak. As a result, unnecessary stress generated when the engaging hole 7sh ... and the transmission pin portion 4p ... Are engaged can be eliminated, and stable and smooth rotation transmission from the transmission pin portion 4p ... To the output plate portion 7 can be performed. At the same time, it is possible to perform highly accurate rotation transmission due to the increased rigidity.

(4) According to a preferred embodiment, when the transmission pin portion 4p ... Is configured, the transmission pin body 4pm ... Protruding from the flex gear portion 4 and the center position are rotatably supported around the transmission pin body 4pm ... If the transmission roller 4pr ... is configured, the contact friction between the transmission pin portion 4p ... and the engagement hole 7sh ... when the transmission pin portion 4p ... engages with the engagement hole 7sh ... can be reduced, so that the flex gear Rotational transmission from the unit 4 to the output plate unit 7 can be efficiently and stably performed, and unnecessary heat generation and wear can be eliminated to improve reliability in long-term use.

(5) If the output plate portion 7 is formed in a ring shape according to a preferred embodiment, it is possible to secure a wiring space for cables Ka, Kb ... This can contribute to the simplification and high rigidity of the overall structure.

(6) According to a preferred embodiment, when the rotation input unit 2 is configured, the inner side of the inner peripheral surface 11i is set as the wiring space S for cables Ka, Kb ..., And at least the oval shaft portion 3 is provided on the outer peripheral surface 11o. If the tubular input rotating body 11 provided with the cam main body 3c is used, the wiring space for the cables Ka, Kb ... Can be secured. As a result, even when the number of cables Ka ... is increased, it is possible to avoid complication of the whole together with other peripheral structures.

(7) According to a preferred embodiment, if the flex gear portion 4 is meshed at two meshing positions T and T having a positional relationship of 180 [°] with respect to the inner gear 5 g of the internal gear portion 5, the flex gear portion is formed. Since 4 can be made into an elliptical shape which is the simplest shape, for example, it is possible to suppress the accuracy required when meshing at three or more meshing positions T ... It is possible to improve the ease of processing and processing, and it is also possible to contribute to the improvement of durability, quietness and reliability.

A perspective view showing a part of the rotation deceleration transmission device according to a basic embodiment for explaining the principle of the rotation deceleration transmission device according to the present invention. Cross-sectional side view showing the whole of the same rotation deceleration transmission device, An exploded perspective view of the main part of the same rotation deceleration transmission device, Front view including a partially extracted enlarged view showing the relationship between the flex gear portion and the internal gear portion of the rotation deceleration transmission device, Operation explanatory view showing a part of the flex gear part of the same rotation deceleration transmission device, Principle cross-sectional configuration diagram in the direction perpendicular to the axis including the oval shaft portion of the rotation deceleration transmission device, Front view including a partially extracted enlarged view showing the relationship between the output plate portion and the transmission pin portion of the rotation deceleration transmission device, Axial cross-sectional view showing a part of the main part of the same rotation deceleration transmission device, External view of an industrial robot using the same rotation deceleration transmission device, Operation explanatory diagram of the same rotation deceleration transmission device, A front view of an output plate portion showing a state in which a transmission pin portion of the rotation deceleration transmission device according to a preferred embodiment of the present invention is engaged. A cross-sectional side view of the output plate portion including a partially extracted enlarged view showing a state in which the transmission pin portion of the rotation deceleration transmission device is engaged. Operation explanatory view of the output plate portion showing the state in which the transmission pin portion of the rotation deceleration transmission device is engaged, Front view showing only a part of the flex gear part of the same rotation deceleration transmission device.

Next, preferred embodiments of the present invention will be given and described in detail with reference to the drawings.

First, in order to facilitate understanding of the rotation deceleration transmission device 1 according to the preferred embodiment, the configuration and operation of the rotation deceleration transmission device 100 according to the basic embodiment will be described with reference to FIGS. 1 to 10.

This type of rotation deceleration transmission device 100, 1 can be used for the joint mechanism Mj of the industrial robot R as shown in FIG. The example industrial robot R is a vertical articulated robot Rv, which drives and controls the robot main body 22 installed on the upper surface of the machine base 21 and the robot main body 22 by accommodating the robot main body 22 in the space below the machine base 21. A robot controller 23 is provided. The robot main body 22 includes a first arm (arbitrary arm) 15 and a second arm (other arm) 16, and the first arm 15 and the second arm 16 are joint mechanisms Mj. It is connected via. That is, the rotation deceleration transmission devices 100 and 1 are built in the tip portion 15s of the first arm portion 15, and the rear end portion 16r of the second arm portion 16 is rotationally driven by the rotation deceleration transmission devices 100 and 1. As a result, positioning control, angle control, speed control, and the like of the second arm portion 16 can be performed.

1 and 2 show the overall structure of the rotation deceleration transmission device 100. In FIG. 2, the tip portion 15s of the first arm portion 15 and the rear end portion 16r of the second arm portion 16 in the industrial robot R shown in FIG. 9 are shown by virtual lines, respectively. As shown in FIGS. 1 and 2, the rotation deceleration transmission device 100 is roughly classified from the rotation input unit 2, the oval shaft portion 3, the flex gear portion 4, the internal gear portion 5, and the rotation output from the upstream side in the rotation transmission direction. A mechanism 6 (output plate portion 7) is provided. As a result, the rotary motion input to the rotary input unit 2 is decelerated at a preset 1/100 to 1/200 level, and the decelerated rotary motion is output from the rotary output mechanism 6.

Hereinafter, the configuration of each part will be specifically described. The rotation input unit 2 is composed of an input rotating body 11 having a tubular shape as a whole. The input rotating body 11 is rotatably supported by a bearing (ball bearing or the like) 31. In this case, the bearing 31 fixes the outer ring to the support cylinder 32 attached to the inner surface of the first arm portion 15, and fixes the inner ring to the outer peripheral surface of the input rotating body 11. As shown in FIG. 2, the input rotating body 11 has a wiring space S for cables Ka, Kb ... Inside the inner peripheral surface 11i. Therefore, the inner diameter and the like can be selected in consideration of the size of the wiring space S to be secured. Further, a cam body portion 3c constituting the oval shaft portion 3 is integrally formed at an intermediate portion in the axial direction Fs on the outer peripheral surface 11o of the input rotating body 11.

Therefore, if such a tubular input rotating body 11 is used, the wiring space S of the cables Ka, Kb ... Can be secured, so that even if the number of cables Ka, Kb ... Is increased, other There is an advantage that it is possible to avoid complication of the whole together with the peripheral structure of. Reference numeral 33 is an input gearing fixed to the end face of the input rotating body 11.

As shown in FIG. 6, the oval shaft portion 3 includes a cam main body portion 3c integrally formed with the input rotating body 11, an inner ring 3bi provided along the outer peripheral surface of the cam main body portion 3c, and a flexible outer ring 3bo. A plurality of rolling elements 3bm ... Intervened between the inner ring 3bi and the outer ring 3bo are provided. The exemplary rolling element 3bm ... Is a ball. The inner ring 3bi can also be used as the outer peripheral surface of the cam main body 3c. As a result, the cross-sectional shape of the inner peripheral surface 11i of the cam body 3c in the direction perpendicular to the axis becomes circular, and the cross-sectional shape of the outer peripheral surface 11o of the cam body 3c in the direction perpendicular to the axis becomes elliptical (oval). (See FIG. 6).

On the other hand, a drive motor 34 such as a servo motor is fixed to the inner surface of the first arm portion 15, and a drive gear 34 g attached to the rotating shaft of the drive motor 34 is meshed with the input gear ring 33. As a result, the rotational motion from the drive motor 34 is input to the input rotating body 11 that is rotatably supported. In this way, if the rotation input unit 2 (input rotating body 11) is made to input the rotational movement of the drive motor 34, the rotation deceleration transmission device 100 can be configured as a drive unit including the drive motor 34. For example, there is an advantage that the drive unit built in the arm portion of the industrial robot can be miniaturized, and further, durability and reliability can be improved. Although the gear transmission mechanism has been exemplified as the rotation transmission method from the drive motor 34 to the rotation input unit 2, other rotation transmission methods such as a belt transmission mechanism using a timing belt and a pulley may be used.

The flex gear portion 4 is entirely formed of a metal material (special steel or the like) into a flexible endless belt shape, and is attached along the outer peripheral surface of the outer ring 3bo of the oval shaft portion 3 as shown in FIG. FIG. 4 shows the overall shape of the flex gear portion 4, and FIG. 5 shows a partially enlarged shape of the flex gear portion 4. The flex gear portion 4 forms an outer gear 4g along the circumferential direction Ff on the outer peripheral surface.

Further, the transmission pin main body 4pm ... Is embedded (press-fitted into the hole) every other tooth portion (mountain portion) 4gs ... constituting the outer gear 4g. In this case, since each tooth portion (mountain portion) 4gs ... has a function of supporting each transmission pin body 4pm ..., a thickness and a shape that can secure the supporting strength are selected. In addition, although the example in which the transmission pin main body 4pm ... Is arranged every other tooth portion (mountain portion) 4gs ... Is shown, the interval between the transmission pin main bodies 4pm ... Can be arbitrarily set. Each transmission pin body 4pm ... is made of a metal material having high rigidity and wear resistance, and is formed in a round bar shape having a circular cross section as shown in FIGS. 3 to 5, and as shown in FIG. One end side is embedded in each tooth portion (mountain portion) 4 gs ..., And the other end side is projected laterally (upward in FIG. 8) from the side surface of the flex gear portion 4. As a result, the transmission pin main bodies 4pm ... Are arranged at regular intervals along the circumferential direction Ff of the flex gear portion 4.

Further, the eccentric position of the transmission roller 4pr ... Is rotatably attached to the other end side of each transmission pin body 4pm ... Protruding from the lateral side of the flex gear portion 4. As a result, the eccentric position of each transmission roller 4pr ... Is rotatably supported by each transmission pin body 4pm. In this way, the transmission pin portion 4p ... Is configured by the transmission pin body 4pm ... Protruding from the flex gear portion 4 and the transmission roller 4pr ... whose eccentric position is rotatably supported around the transmission pin body 4pm ... Will be done. It is desirable that the transmission pin portion 4p ... is composed of such a transmission pin body 4pm ... and a transmission roller 4pr ..., but the shape of the transmission pin body 4pm ... is selected and integrated without using the transmission roller 4pr ... It may be the transmission pin portion 4p ...

On the other hand, on the inner peripheral surface of the flex gear portion 4, each position corresponding to the valley portion 4 gd ... between each tooth portion (mountain portion) 4 gs ... has a U-shape as shown in FIG. The cut portion 4c ... Is formed in the radial direction Fd. As a result, the thickness between each valley portion 4gd ... and each notch portion 4c ... ensures flexibility (elasticity) capable of smoothly and stably following the rotation of the oval shaft portion 3. The solid line portion in FIG. 5 shows the shape when the flex gear portion 4 shown in FIG. 4 is the furthest away from the internal gear portion 5, and the virtual line portion in FIG. 5 shows the shape of the flex gear portion 4 shown in FIG. 4 as the internal gear. The shape when the part 5 is closest to the portion 5 is shown.

The entire internal gear portion 5 is formed in a ring shape having rigidity by a metal material, and as shown in FIG. 3, an inner gear 5 g along the circumferential direction Ff is formed on the inner peripheral surface. Then, as shown in FIG. 2, the outer peripheral surface of the internal gear portion 5 is attached and fixed to the inner surface of the first arm portion 15, and the inner gear 5 g is engaged with the outer gear 4 g of the flex gear portion 4 described above. At this time, the number of teeth around the inner gear 5g formed on the internal gear portion 5 is set to be larger than the number of teeth around the outer gear 4g formed on the flex gear portion 4. In the example, the number of teeth of the outer gear 4g was set to "N", and the number of teeth of the inner gear 5g was set to "N + 2".

In this case, since the outer peripheral shape of the flex gear portion 4 is elliptical, the flex gear portion 4 meshes at two meshing positions T and T having a positional relationship of 180 [°] with respect to the inner gear 5g. .. In this way, if the flex gear portion 4 is meshed at two meshing positions T and T having a positional relationship of 180 [°] with respect to the inner gear 5 g, the flex gear portion 4 can be made the simplest. Since the elliptical shape to be the shape can be selected, for example, the accuracy required for meshing at three or more meshing positions T ... can be suppressed to be lower, and the ease of manufacturing and processing can be improved. At the same time, it has the advantage of contributing to the improvement of durability, quietness and reliability.

The rotary output mechanism 6 includes an output plate holder 12 formed in a ring shape, and the output plate holder 12 is provided by a bearing (roller bearing) 36 arranged between the inner peripheral surface and the outer peripheral surface of the input rotating body 11. The inner peripheral surface side is supported, and the outer peripheral surface side is supported by the cross roller bearing 37 arranged between the outer peripheral surface of the output plate holder 12 and the inner surface of the first arm portion 15. A ring recess 12h for fitting the output plate portion 7 is formed on the end surface 12s of the output plate holder 12 facing the flex gear portion 4, and the output plate portion 7 shown in FIG. 2 is fitted in the ring recess 12h. Let me. On the other hand, the output connection plate 38 is fixed to the end surface 12t opposite to the end surface 12s having the ring recess 12h in the output plate holder 12.

Further, the output plate portion 7 is formed in a ring shape (ring plate shape), and a plurality of engaging holes 7sh ... to which the transmission roller 4pr ... Can be engaged are formed. The engagement holes 7sh ... Are formed at predetermined intervals along the circumferential direction Ff of the output plate portion 7, and the radial direction Fd ... can be allowed to be displaced when the output plate portion 7 rotates. It is formed as a slit-shaped elongated hole along the line. If the output plate portion 7 is formed in a ring shape, a wiring space for cables Ka, Kb ... Can be secured, and in particular, by combining with the input rotating body 11 formed in a tubular shape, the overall structure can be secured. It has the advantage of contributing to simplification and high rigidity. In addition, in FIGS. 1 and 2, reference numeral 40 ... Indicates a seal ring.

In this way, when the rotary output mechanism 6 is configured, the transmission roller 4pr ... Which supports the eccentric position with the transmission pin body 4pm ... As the axis, and the transmission roller 4pr ... Are engaged and along the circumferential direction Ff. If a plurality of engaging holes 7sh ... that are formed at predetermined intervals and allow displacement of the transmission roller 4pr ... During rotation transmission are provided by using a ring-shaped output plate portion 7 provided in the radial direction Fd, the circumference It is possible to effectively absorb the displacement of the transmission pin portion 4p ... With respect to the engagement holes 7sh ... generated at different positions in the directions Ff. Therefore, unnecessary stress generated when the engaging hole 7sh ... and the transmission pin body 4pm ... Are directly engaged with each other is eliminated, and the rotation transmission from the transmission pin portion 4p ... To the rotation output mechanism 6 is performed stably and smoothly. At the same time, unnecessary loss can be eliminated and the rotation transmission efficiency can be further improved.

Therefore, according to the rotation deceleration transmission device 100 according to such a basic form, the rotation input unit 2 for inputting the rotational motion, the cam body 3c that rotates integrally with the rotation input 2, and the cam body 3c. An oval shaft portion 3 in which a plurality of rolling elements 3bm ... Are interposed between an inner ring 3bi and a flexible outer ring 3bo provided along the outer circumference of the inner gear 5 and an internal gear portion 5 having an inner gear 5g formed on the inner circumference and a fixed position. When it is formed along the circumferential direction Ff of the outer circumference and the number of teeth is reduced with respect to the inner gear 5 g and attached to the outer periphery of the oval shaft portion 3, two places (generally a plurality of places) in the circumferential direction Ff. A plurality of transmission pin main bodies 4 pm ... and the transmission pin main body 4 pm ... The flex gear portion 4 having the transmission pin portion 4p ... configured by the transmission roller 4pr ... whose eccentric position is rotatably supported about the axis, and the transmission pin portion 4p ... are engaged and in the circumferential direction Ff. In order to provide a rotation output mechanism 6 having an output plate portion 7 provided with a plurality of engagement holes 7sh ... in the radial direction Fd that allow displacement of the transmission pin portion 4p ... , The conventional flexspline that forms the whole shape into a cup shape by using a thin metal elastic plate material becomes unnecessary.

As a result, it can be easily manufactured, the manufacturing cost can be significantly reduced, and metal fatigue and malfunctions can be significantly reduced. Therefore, durability and reliability can be improved, and initial cost and running can be improved. It is possible to realize a significant cost reduction in terms of both costs. Moreover, since the conventional flexspline is not required, the size of the arrangement space in the axial direction Fs can be reduced, and the overall structure can be made thinner. Therefore, further miniaturization of industrial robots and the like, which has a limit in miniaturization, can be easily realized.

Further, if the rotation deceleration transmission device 100 is used for the joint mechanism Mj that connects an arbitrary arm portion 15 constituting the robot R and another arm portion 16, the joint mechanism Mj is made thinner (miniaturized), durable and reliable. Since it can contribute to the improvement of performance, there is an advantage that an optimum industrial robot (vertical articulated robot Rv, horizontal articulated robot, delta type robot, etc.) for installation on a production line can be constructed.

Next, the operation of the rotation deceleration transmission device 100 having such a basic form will be described mainly with reference to FIGS. 10 (a) to 10 (d) with reference to FIGS. 1 to 9. Since FIGS. 10A to 10D are principle diagrams, the elliptical shape of the cam body 3c is drawn as an exaggerated elongated shape.

First, if the drive motor 34 is ON-controlled by the robot controller 23, the drive motor 34 operates and the drive gear 34g rotates. This rotational motion is transmitted to the input gearing 33 and further transmitted to the input rotating body 11 including the cam main body 3c. As a result, the cam body 3c rotates at a relatively high speed.

FIG. 10A shows a state before the rotation of the cam main body 3c starts. In this state, the cam main body 3c stops at the position Ps, and the longitudinal direction (maximum direction of the elliptical diameter) of the cam main body 3c is the vertical direction. Therefore, the start point in the flex gear portion 4 is at the position of the symbol Xs and coincides with the reference point Xo in the internal gear portion 5. In the state of FIG. 10A, the outer gear 4g of the flex gear portion 4 meshes with the inner gear 5g of the internal gear portion 5 at two upper and lower meshing positions T and T.

Next, it is assumed that the cam main body 3c is rotated by 90 ° in the direction of the arrow Dr from the position Ps in FIG. 10 (a). This state is shown in FIG. 10 (b). In this case, the cam body 3c is displaced from the position Ps to the position P1 rotated 90 ° clockwise. As a result, the longitudinal direction of the cam main body 3c becomes the left-right direction as shown in FIG. 10 (b). Therefore, when the cam body 3c is rotated, the upper meshing position T (the same applies to the lower meshing position T) at which the outer gear 4g meshes with the inner gear 5g moves 90 ° while meshing clockwise. At this time, since the number of teeth of the outer gear 4g is N and the number of teeth of the inner gear 5g is N + 2, the starting point of the flex gear portion 4 is an angle Q1 = (360 ° / N) × 2) / 4 with respect to the reference point Xo. Only, it is displaced to the position X1 in the counterclockwise direction.

Further, it is assumed that the cam main body 3c is rotated by 90 ° in the direction of the arrow Dr from the position P1 in FIG. 10 (b). This state is shown in FIG. 10 (c). In this case, the cam body 3c is displaced from the position P1 to the position P2 rotated 90 ° clockwise. As a result, the longitudinal direction of the cam main body 3c becomes the vertical direction as shown in FIG. 10 (c). Therefore, the start point of the flex gear portion 4 is displaced to the position X2 in the counterclockwise direction by an angle Q2 = (360 ° / N) × 2) / 2 with respect to the reference point Xo.

Next, it is assumed that the cam main body 3c is rotated 180 ° in the direction of the arrow Dr from the state shown in FIG. 10 (c). This state is shown in FIG. 10 (d). In this case, the cam main body 3c is displaced from the position P2 to the position P3 rotated by 180 °. As a result, the longitudinal direction of the cam main body 3c becomes the vertical direction, and the cam main body portion 3c is turned upside down with respect to the position shown in FIG. 10 (c). Therefore, the starting point of the flex gear portion 4 is displaced to the position X3 which is counterclockwise by an angle Q3 = (360 ° / N) × 2) with respect to the reference point Xo. As described above, the cam main body portion 3c is rotated once in the clockwise direction, and the flex gear portion 4 is subjected to the deceleration process of moving in the counterclockwise direction by the number of teeth "2".

Further, the decelerated rotational motion of the flex gear portion 4 is transmitted to the rotational output mechanism 6. That is, since the transmission pin portion 4p ... projecting from the flex gear portion 4 includes a transmission roller 4pr ... in which the eccentric position engaged with the engagement hole 7sh ... of the output plate portion 7 is supported, the output plate portion 7 is flexed. It rotates completely in synchronization with the rotational movement of the gear portion 4. In this case, the transmission pin portion 4p ... Is repeatedly displaced in the radial direction Dd according to the locus of the outer peripheral surface of the cam main body portion 3c, and this displacement is absorbed by the engaging holes 7sh ... formed by the elongated holes.

Then, as shown in FIG. 2, the rotational movement of the output plate portion 7 is greatly decelerated with respect to the input rotational movement, and the rotation other than the output plate portion 7 including the output plate holder 12 and the output connection plate 38 is rotated. It is transmitted to the second arm portion 16 via the output mechanism 6, and the second arm portion 16 is rotationally displaced. That is, the rotation is controlled with high accuracy with the first arm portion 15 as a fulcrum.

Next, based on such a basic embodiment, the rotation deceleration transmission device 1 according to the preferred embodiment of the present invention will be described in detail with reference to FIGS. 11 to 14.

This embodiment is different from the above-mentioned basic embodiment in that the transmission pin portion 4p ... And the output plate portion 7 are changed. That is, as shown in FIGS. 11 to 14, the present embodiment includes a flex gear portion 4 having a plurality of transmission pin portions 4p ... Protruding from the side surface and provided at predetermined intervals along the circumferential direction Ff. , Each transmission pin portion 4p ... is engaged, and is provided at predetermined intervals along the circumferential direction Ff, and an engagement hole 7sh ... is formed to allow displacement of the transmission pin portion 4p ... during rotation transmission. The basic configuration having the output plate portion 7 provided with the portions 7s ... Is the same as the basic form, but the following points are different.

First, when configuring the transmission pin portion 4p, in the basic embodiment, a configuration is adopted in which the transmission pin body 4pm supports the eccentric position of the transmission roller 4pr, but in the first embodiment, the transmission pin portion 4p is configured. At this time, it was composed of a transmission pin main body 4 pm protruding from the flex gear portion 4 and a transmission roller 4 pr whose center position is rotatably supported around the transmission pin main body 4 pm. Therefore, the contact friction between the transmission pin portion 4p ... and the engagement hole 7sh ... when the transmission pin portion 4p ... engages with the engagement hole 7sh ... Can be reduced, so that the flex gear portion 4 to the output plate portion 7 can be reduced. Similar to the basic form, rotation transmission can be performed efficiently and stably, and unnecessary heat generation and wear can be eliminated to improve reliability in long-term use.

Secondly, when a plurality of engaging holes 7sh ... Formed at predetermined intervals along the circumferential direction Ff of the output plate portion 7 formed in the shape of a ring plate are provided, in the basic form, when the output plate portion 7 rotates. In order to allow the displacement of the transmission roller 4pr ... Of the above, the transmission pin portion 4p ... The peripheral surface (the peripheral surface of the transmission roller 4pr ...) is always in contact with the output plate portion 7, and the bidirectional engaging hole 7sm ... Formed by

That is, as shown in FIG. 13, each bidirectional engaging hole 7sm ... Is formed at intervals of Qs [°] (in the example, 14.4 [°]) along the circumferential direction Ff of the output plate portion 7. Therefore, for example, in the range Zs of about 1/4 circumference, seven bidirectional engaging holes 7sm ... Are formed. Therefore, as shown in FIG. 13, in the bidirectional engaging hole 7sm located at the uppermost portion, the upper end position of the transmission roller 4pr comes into contact at the contact position X1 which is the upper end of the inner surface of the bidirectional engaging hole 7sm. It is assumed that Assuming that the rotation direction of the output plate portion 7 is clockwise, the cam body portion 3c rotates by Qs [°], so that the contact position X2 between the transmission roller 4pr and the bidirectional engagement hole 7sm becomes. The angle is displaced by Qs [°] in the counterclockwise direction when viewed from the transmission roller 4pr. Similarly, as the cam body 3c rotates by Qs [°] × 2, the contact position X3 between the transmission roller 4pr and the bidirectional engagement hole 7sm is Qs [counterclockwise when viewed from the transmission roller 4pr. The cam body 3c is displaced by Qs [°] x 2 and the cam body 3c is rotated by Qs [°] x 3, so that the contact position X4 between the transmission roller 4pr and the bidirectional engagement hole 7sm is from the transmission roller 4pr. Seen, it is displaced counterclockwise by Qs [°] × 3. Then, if the cam body 3c rotates by Qs [°] × 6, the contact position X7 between the transmission roller 4pr and the bidirectional engagement hole 7sm is Qs [°] counterclockwise when viewed from the transmission roller 4pr. Displace by × 6 and make about 1/4 lap. Note that X5 and X6 also indicate contact positions in the middle.

Therefore, in the shape of the bidirectional engaging hole 7sm, the outer peripheral surface of the transmission roller 4pr hits the inner peripheral surface of the bidirectional engaging hole 7sm at any angle position of 360 [°] where the cam body 3c rotates. It may be formed so as to be in contact with each other, particularly with a uniform pressure at all times. Therefore, when forming the multi-directional engaging hole 7sm, high machining accuracy (shape accuracy) is required, but the circumferential direction of the transmission pin portion 4p ... With respect to the engaging hole 7sh ... generated at different positions in the circumferential direction Ff. Since the displacements of Ff and the radial direction Fd can be absorbed by the cam method, unnecessary stress generated when the engaging hole 7sh ... and the transmission pin portion 4p ... are engaged is eliminated, and the output is output from the transmission pin portion 4p ... There is an advantage that stable and smooth rotation transmission to the plate portion 7 can be performed, and in particular, highly accurate rotation transmission can be performed due to increased rigidity.

Further, FIG. 14 shows the flex gear portion 4 used in the present embodiment, but with respect to the basic embodiment, each cut portion 4c ... Is formed wider and between the cut portions 4c ... , The point where each transmission pin body 4pm ... Is arranged is shown as a different example of modification. In addition, in FIGS. 11 to 14, the same parts as those in FIGS. 1 to 10 are designated by the same reference numerals to clarify their configurations, and detailed description thereof will be omitted.

Therefore, according to the rotation deceleration transmission device 1 according to the present embodiment, in particular, as a basic configuration, a rotation input unit 2 for inputting rotational motion and a cam body unit 3c that rotates integrally with the rotation input unit 2 , And an oval shaft portion 3 in which a plurality of rolling elements 3bm ... Are interposed between an inner ring 3bi provided along the outer circumference of the cam main body 3c and a flexible outer ring 3bo, and an inner gear 5g are formed on the inner circumference and are positioned. When attached to the outer periphery of the oval shaft portion 3 by forming the internal gear portion 5 fixed to the internal gear portion 5 along the circumferential direction Ff of the outer circumference and reducing the number of teeth with respect to the inner gear 5g, a plurality of parts in the circumferential direction Ff. A flex gear portion 4 having an outer gear 4 g that meshes with the inner gear 5 g at the meshing position T ... Engagement holes in which transmission pin portions 4p ... Are engaged and are provided at predetermined intervals along the circumferential direction Ff, and allow displacement of the transmission pin portions 4p ... in the circumferential direction Ff and / or radial direction Fd during rotation transmission. Since it is provided with a rotation output mechanism 6 having an output plate portion 7 provided with an engaging portion 7s ... Can be done.

That is, since the conventional flexspline that forms the entire shape into a cup shape using a thin metal elastic plate material becomes unnecessary, it can be easily manufactured, the manufacturing cost can be significantly reduced, and metal fatigue and malfunction can be achieved. Etc. can be significantly reduced, so that durability and reliability can be improved, and a significant cost reduction in both initial cost and running cost can be realized. Further, since the conventional flexspline is not required, the size of the arrangement space in the axial direction Fs can be reduced. Therefore, the overall structure can be made thinner, and further miniaturization of industrial robots and the like, which has a limit in miniaturization, can be easily realized.

Although the preferred embodiment has been described in detail above, the present invention is not limited to such an embodiment, and the present invention does not deviate from the gist of the present invention in terms of detailed configuration, shape, material, quantity, numerical value, and the like. It can be changed, added, or deleted as desired within the range.

For example, the transmission pin portion 4p ... is composed of a transmission pin main body 4pm ... Protruding from the flex gear portion 4 and a transmission roller 4pr ... In which the center position is rotatably supported around the transmission pin main body 4pm ... Although the case has been shown, the integrated transmission pin portion 4p ... may be configured by selecting the shape of the transmission pin body 4pm ... Without using the transmission roller 4pr .... Further, although the case where the flex gear portion 4 is engaged with the inner gear 5 g of the internal gear portion 5 at two meshing positions T and T having a positional relationship of 180 [°] is illustrated, the shape of the cam main body portion 3c is illustrated. Can be formed into a triangular shape, a square shape, or a pentagonal shape, and can be meshed at three meshing positions T ..., four meshing positions T ..., or five meshing positions T .... Further, the rotary output mechanism 6 is provided with a ring-shaped output plate holder 12 that is rotatably supported and has a ring recess 12h formed on the end surface 12s to hold the output plate portion 7. , It does not exclude the case of replacement by another configuration capable of exhibiting the same function. Further, although each transmission pin 4p ... Is provided corresponding to the position of each tooth portion (mountain portion) 4gs in the outer gear 4g, it is not always necessary to correspond the position and each transmission pin 4p ... The quantity and interval need not match the quantity and interval of each tooth portion (mountain portion) 4 gs. On the other hand, although the rotary motion of the drive motor 34 is illustrated as the rotary motion to be input, various other rotary motion sources can be applied. Further, although a metal material is exemplified as a material for forming each part, a synthetic resin material, a fiber reinforced composite material, or the like may be used, or a ceramic material or the like may be used for parts that do not require elasticity. Not limited. It should be noted that, on the inner peripheral surface of the flex gear portion 4, a U-shaped cut portion 4c ... Although the case of forming the Fd is illustrated, the shape and position (interval) of the cut portion 4c ... Are arbitrary, and it is not always necessary to provide the cut portion 4c.

The rotation deceleration transmission device according to the present invention can be used as various rotation deceleration transmission devices that require a function of decelerating and outputting an input rotational movement, including a joint mechanism for connecting an arm portion of an industrial robot.

1: Rotational deceleration transmission device, 2: Rotational input section, 3: Oval shaft section, 3c: Cam body section, 3bi: Inner ring, 3bo: Outer ring, 3bm ...: Rolling element, 4: Flex gear section, 4g: Outer gear, 4p ...: Transmission pin part, 4pm ...: Transmission pin body, 4pr ...: Transmission roller, 5: Internal gear part, 5g: Inner gear, 6: Rotational output mechanism, 7: Output plate part, 7s ...: Engagement part, 7sh ... : Engagement hole, 7sm ...: Multi-directional engagement hole, 11: Input rotating body, 11i: Inner peripheral surface, 11o: Outer peripheral surface, Ff: Circumferential direction, Fd: Radiation direction, Fs: Axial direction, T ...: Engagement Position, Ka: Cables, Kb: Cables, S: Wiring space

Claims (5)

It is a rotation deceleration transmission device that decelerates and outputs the input rotational motion, along the rotary input unit to which the rotational motion is input, the cam body unit that rotates integrally with the rotation input unit, and the outer circumference of the cam body unit. An oval shaft portion in which a plurality of rolling elements are interposed between the inner ring and the flexible outer ring provided therein, an internal gear portion in which an inner gear is formed on the inner circumference and a fixed position is formed, and an internal gear portion formed along the circumferential direction of the outer circumference. In addition, when the number of teeth is reduced with respect to the inner gear and the oval shaft portion is attached to the outer periphery, the outer gear has an outer gear that meshes with the inner gear at a plurality of meshing positions in the circumferential direction, and also protrudes from the side surface and rotates. A flex gear portion having a plurality of transmission pin portions provided at predetermined intervals along the direction and each transmission pin portion are engaged with each other and are provided at predetermined intervals along the circumferential direction, and the transmission pins are provided at predetermined intervals during rotation transmission. A rotary output mechanism having an output plate portion provided with an engaging portion having an engaging hole formed with an engaging hole that allows displacement in the circumferential direction and / or the radial direction of the portion is provided, and the engaging portion is provided on the output plate portion. By forming, the peripheral surface of the transmission pin portion is always in contact with the output plate portion, and the output plate portion is composed of a multi-directional engaging hole that allows displacement of the transmission pin portion in the circumferential direction and the radial direction. A rotation deceleration transmission device characterized by becoming. The first aspect of the present invention, wherein the transmission pin portion is composed of a transmission pin main body protruding from the flex gear portion and a transmission roller whose center position is rotatably supported around the transmission pin main body. Rotation deceleration transmission device. The rotation deceleration transmission device according to claim 1, wherein the output plate portion is formed in a ring shape. The rotation input portion is composed of a tubular input rotating body having an inner peripheral surface formed in a wiring space for cables and at least a cam main body portion of the oval shaft portion provided on an outer peripheral surface. The rotation deceleration transmission device according to claim 1. The rotation deceleration transmission device according to claim 1, wherein the flex gear portion is meshed at two meshing positions having a positional relationship of 180 [°] with respect to the inner gear of the internal gear portion.

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