JP2009121494A - Double-stage reduction gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double-stage reduction gear capable of realizing an extensive range from a small reduction gear ratio to a large reduction gear ratio without generating any backlash with a simple constitution favorably in a cost aspect. <P>SOLUTION: When a crank input shaft 4 is rotated, the compound motion of a first eccentric gear 2 is transmitted to a second eccentric gear 11 via a first speed change crank shaft 10A, and a parallel biaxial constant velocity joint 13 is functioned to transmit the rotational displacement out of the compound motion of the first eccentric gear 2 to the second eccentric gear 11 at the transmission ratio of 1:1. The second eccentric gear 11 also performs the compound motion, and a second ring gear 12 outputs the rotation displacement by the rotational displacement of the second eccentric gear 11. The rotational displacement of the first eccentric gear 2 is divided by the ratio of the number of external teeth of the second eccentric gear 11 to the number of internal teeth of the second ring gear 12, and the speed reduction of the first eccentric gear 2 can be realized in an extensive range from the small value to the large value. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a multistage speed reduction device that can set a wide speed ratio from a small speed reduction ratio to a large speed reduction ratio by decelerating to a plurality of speeds.

  The multistage speed reducer is used to transmit rotation of servomotors and drive precision processing machines. In addition to the speed reduction function and rotation transmission function, the multistage speed reducer loads the driven member with high accuracy without causing backlash. It is required to communicate. In particular, in order to obtain a large speed reduction (or a small speed reduction ratio), in a multi-stage speed reduction device to which a planetary gear mechanism having a hypocycloidal tooth profile is applied, the transmission mechanism by meshing the planetary gear and the internal gear becomes complicated, and the rotation speed It is known that it is not easy to achieve smooth and highly accurate rotation without play (see, for example, Patent Document 1).

As a typical multistage speed reducer, for example, there is a mysterious planetary gear mechanism speed reducer disclosed in Patent Document 2. This reduction device includes a plurality of first planetary gears meshed with a fixed internal gear and a plurality of second planetary gears meshed with a movable internal gear, and the fixed internal gear and the movable internal gear are arranged coaxially.
A sun gear meshing with a plurality of first planetary gears is provided, and the first planetary gear is connected to the second planetary gear via a rotating shaft and a carrier. A phase difference is provided between the tooth profile position of the second planetary gear and the tooth profile position of the first planetary gear. The first planetary gear is rotated by the rotation of the sun gear, and this rotation rotates the second planetary gear via the rotating shaft to rotate the movable internal gear. Thereby, it is said that the reduction ratio can be reduced to 1/3 of the reduction gear of a normal wonder planetary gear mechanism.

In addition, the differential gear speed reduction mechanism 100 shown in FIG. 16 includes a first internal gear 102 disposed with a predetermined diameter on the first external gear 101 and an input shaft 104 (crankshaft) having an eccentric portion 103. . The first external gear 101 is fixed, and the first internal gear 102 and the second internal gear 105 having the same diameter are connected by a connecting shaft 102A. The second internal gear 105 meshes with a second external gear 106 that can freely rotate.
As indicated by an arrow Sp in FIG. 16, when the input shaft 104 is rotated in the clockwise direction, the first internal gear 102 performs a combined motion involving a rotational displacement in the arrow T direction and a turning displacement in the arrow U direction. This combined motion is transmitted to the second internal gear 105 via the connecting shaft 102A, and only the rotation component is transmitted to the second external gear 106 to rotate the output shaft 107 in the arrow V direction together with the second external gear 106.
JP-A-5-79537 JP 2005-16695 A

In Patent Document 1, as described above, the transmission mechanism by meshing the planetary gear and the internal gear becomes complicated, and it is not easy to achieve smooth and high-precision rotation without play of rotation. It is not suitable for mounting and using.
In Patent Document 2, although the speed reduction ratio can be significantly reduced, judging from the connection structure of the first planetary gear and the second planetary gear, it causes meshing interference, resulting in poor balance and smooth rotation transmission. Inferior, there is a risk of trouble during high-speed rotation.

  In the differential gear reduction mechanism 100 of FIG. 16, if the first internal gear 102 and the second internal gear 105 can be gears having different numbers of teeth, a double-type (two-stage reduction) differential gear reduction mechanism is established. There is an advantage that the reduction ratio can be significantly reduced. In this case, if the number of teeth of the first external gear 101 is A1, the number of teeth of the first internal gear 102 is B1, the number of teeth of the second internal gear 105 is C1, and the second external gear 106 is D1, the reduction ratio is 1− {A1 × C1 / (B1 × D1)}.

For this reason, a mechanism for providing an eccentric crank portion on the connecting shaft 102A and decelerating the first internal gear 102 in two stages has been considered, and research, trial manufacture, and experiments have been repeated. Although this mechanism has little meshing interference and lacks smooth rotation, it can be decelerated. Therefore, if the backlash is set large, it cannot be put to practical use.
However, it is accompanied by noise and vibration, and must be sacrificed for stable and reliable operation, high accuracy and longevity when decelerating. In many ways, it is applied to industrial robots and precision automatic assembly machines. There was room for improvement.

  The present invention has been made in consideration of the above circumstances, and its purpose is to realize a wide range of speed ratios from a small reduction ratio to a large reduction ratio without causing backlash, with a simple configuration, and cost-effectively. In addition, it is an object of the present invention to provide a multistage speed reducer that is free from noise and vibrations, has a smooth and stable overall rotation during deceleration, and can achieve highly reliable operation, excellent rotation transmission accuracy, and long life.

(About claim 1)
The first eccentric gear has a crank input shaft and meshes with the internal teeth of the fixed first ring gear, and performs a combined motion including rotational displacement and turning displacement as the crank input shaft rotates. The second eccentric gear is connected to the first eccentric gear in an eccentric state with the crank input shaft, and is provided so as to be freely rotatable with a different number of teeth from the inner teeth of the first ring gear, and to the inner teeth of the second ring gear. Mesh. The first transmission crankshaft is provided so as to connect the first eccentric gear and the second eccentric gear. The parallel biaxial constant velocity rotary joint connects between the first eccentric gear and the second eccentric gear, and is arranged so as to transmit the combined motion of the first eccentric gear to the second eccentric gear at a transmission ratio of 1: 1. Has been.
The inner ring pitch circle of the first ring gear and the internal ring pitch circle of the second ring gear are set to the same size, and the rotational displacement of the combined movement of the first eccentric gear is changed to the first speed change with the rotation of the crank input shaft. The torque is transmitted to the second eccentric gear through the crankshaft and the parallel two-axis constant velocity rotary joint so that the second ring gear outputs a rotational displacement.

  In this configuration, when the combined motion of the first eccentric gear is transmitted to the second eccentric gear via the first transmission crankshaft as the crank input shaft rotates, the parallel biaxial constant velocity rotary joint functions, and the first eccentric gear Of the combined movement of the gear, the rotational displacement is transmitted to the second eccentric gear at a transmission ratio of 1: 1. As a result, the second eccentric gear also performs a compound motion, and the second ring gear outputs a rotational displacement due to the rotational displacement of the second eccentric gear.

At this time, the rotational displacement of the first eccentric gear is divided by the ratio of the number of external teeth of the second eccentric gear and the number of internal teeth of the second ring gear, so that the first eccentric gear can be reduced in a wide range from a small width. You can slow down. That is, since the reduction ratio can be set at a reduction ratio that depends on the number of teeth of the first eccentric gear, the first ring gear, the second eccentric gear, and the second ring gear, a wide range from a small reduction ratio to a large reduction ratio. Speed ratio is realized.
While realizing a wide range of speed ratios, a simple configuration in which a parallel biaxial constant velocity rotary joint is provided between the first eccentric gear and the second eccentric gear is sufficient, which is advantageous for mass production with reduced manufacturing costs. It becomes.

  During the deceleration operation, the parallel biaxial constant velocity rotary joint reliably transmits the rotational displacement of the first eccentric gear to the second eccentric gear with a transmission ratio of 1: 1. For this reason, the second eccentric gear does not interfere with the second ring gear, engages securely in a normal state, does not generate noise vibration, and the entire rotation is smooth and stable during deceleration, and operation with high reliability. Excellent rotation transmission accuracy and long life can be achieved.

(About claim 2)
In the parallel biaxial constant velocity rotary joint, a series of circular hole groups are provided along the same pitch circle on the outer surface of the first eccentric gear and the outer surface of the second eccentric gear that face each other. The circular rotation transmission body is loosely fitted so as to be able to roll over the circular hole of the first eccentric gear and the circular hole of the second eccentric gear, and the first eccentric gear and the second eccentric gear with respect to the inner peripheral surface of the circular hole. There is a gap according to the amount of eccentricity.
As the crank input shaft rotates, the rotation transmission body rolls on the inner peripheral surfaces of the circular hole of the first eccentric gear and the circular hole of the second eccentric gear, thereby reducing the rotational displacement of the combined motion of the first eccentric gear to 1 It is transmitted to the second eccentric gear at a transmission ratio of one to one.

  In this case, the parallel biaxial constant velocity rotary joint has a simple structure in which a circular hole group is provided in the first eccentric gear and the second eccentric gear so that the rotation transmitting body is loosely fitted in the circular hole, thereby saving space and reducing costs. Can be realized.

(Claim 3)
The first eccentric gear and the second eccentric gear are external pinions, and the first ring gear and the second ring gear are pin pinions.
In this case, the difference in the number of teeth between the first eccentric gear and the first ring gear and the difference in the number of teeth between the second eccentric gear and the second ring gear can be easily set large, which is suitable for realizing a large speed ratio.

(About claim 4)
The fixed disk has a cycloid-type first curved tooth groove formed on one side thereof in a circumferential direction along a first pitch circle. The first speed change disk is connected to an input shaft in close proximity to the fixed disk in an eccentric state with a first eccentric amount, and a second pitch circle that is the same as the first pitch circle on a surface portion corresponding to the first curved tooth groove. A cycloid-based second curved tooth gap having a wave number difference of one or two is formed along the top.

The plurality of first rolling balls are arranged between the first curved tooth groove and the second curved tooth groove, and with the rotation of the input shaft, the rotation displacement and the turning displacement of the first speed change disk with respect to the fixed disk. A complex motion consisting of
The second speed change disk is made of a cycloid system formed in the circumferential direction along the third pitch circle on the opposite side to the face facing the first speed change disk with a second eccentric amount. It has a 3rd curve tooth gap.

  The parallel biaxial constant velocity rotary joint is provided between the first transmission disk and the second transmission disk, and transmits the combined motion of the first transmission disk to the second transmission disk at a transmission ratio of 1: 1. The output disk has an output shaft, and is provided on the second speed change disk so as to face the eccentric state with a third eccentric amount, and has a first pitch of the same size as the third pitch circle on the surface portion facing the third curved tooth groove. It is formed in a circumferential direction along a 4-pitch circle, and has a fourth curved tooth groove of a cycloid system having one wave number difference from the third curved tooth groove.

The plurality of second rolling balls are arranged over the third curved tooth gap and the fourth curved tooth groove, and absorb the turning movement of the combined movement of the second speed change disk and output only the rotation displacement from the output disk. Let
A first collective force point is set at which the normal lines of the tangential lines that form pressure angles by the first rolling balls coming into contact with the first curved tooth groove of the fixed disk and the second curved tooth groove of the first speed change disk at one point. To do. A second collective force point at which the normal lines of the tangential lines that form the pressure angle by the engagement of the second rolling balls with the third curved tooth groove of the second speed change disk and the fourth curved tooth groove of the output disk intersect at one point is set. To do. The distance from the first eccentric position of the first eccentric amount to the first collective force point is made equal to the distance from the third eccentric position of the third eccentric amount to the second collective force point.

  In this case, with the rotation input to the input shaft, the first speed change disk rolls the first rolling ball with respect to the first curved tooth groove and the second curved tooth groove, and includes a combined motion including rotational displacement and turning displacement. I do. The combined motion of the first speed change disk is transmitted to the second speed change disk at a transmission ratio of 1: 1 as a rotational displacement by a parallel biaxial constant velocity rotary joint. The second speed change disc to which the rotational displacement is transmitted, while rolling the second rolling ball along the third curved tooth groove and the fourth curved tooth groove, performs a combined motion to absorb the turning displacement, and only the rotational displacement. Tell the output disc to rotate the output shaft.

  At this time, the rotational displacement of the first speed change disk is decelerated based on the wave number ratio between the first curved tooth gap and the second curved tooth groove, and further between the third curved tooth groove and the fourth curved tooth groove. It is decelerated based on the wave number ratio. As a result, the output disk can be rotated by decelerating the first speed change disk over a wide range from small to large.

That is, the speed reduction ratio can be set at a speed reduction ratio depending on each wave number of the first speed change disk and the second speed change disk, so that a wide speed ratio can be realized from a small speed reduction ratio to a large speed reduction ratio.
While realizing a wide range of speed ratios, a simple configuration in which a parallel biaxial constant velocity rotary joint is provided between the first speed change disk and the second speed change disk is sufficient, which is advantageous for mass production with reduced manufacturing costs. It becomes.

  During deceleration operation, the parallel biaxial constant velocity rotary joint reliably transmits the rotational displacement of the first transmission disk to the second transmission disk at a ratio of 1: 1. For this reason, the second rolling ball does not interfere with the first curved tooth gap and the second curved tooth groove, and it is engaged with each other in a proper state without causing backlash and smoothly rolls. As a result, no noise vibration is generated, the rotation is stabilized during deceleration, and a highly reliable operation, excellent rotation transmission accuracy and long life can be achieved.

(Claim 5)
In the parallel biaxial constant velocity rotary joint, a series of circular hole groups having a radial dimension corresponding to the second eccentric amount are formed along the same pitch circle on the first transmission disk and the second transmission disk which are overlapped with each other. Has been. The plurality of rolling ball bodies are arranged so as to roll over a circular hole of the first speed change disk and a circular hole of the second speed change disk, and the second movement of the first speed change disk is performed at a transmission ratio of 1: 1. Tell the shifting disc.

  In this case, the parallel biaxial constant velocity rotary joint has a simple structure in which a series of circular hole groups are respectively formed in the first transmission disk and the second transmission disk, and a rolling ball body is provided in the circular hole. This makes it compact and saves space and costs.

(About claim 6)
The first external tooth pinion has first pinion teeth meshing with the internal teeth of the first pin pinion formed on the outer peripheral portion by a tooth surface profile based on a cycloid system curve, and swivel displacement and rotation while meshing with the first pin pinion. It is arranged in an eccentric state so as to perform a combined motion consisting of displacement. The second external tooth pinion has a second pinion tooth that is juxtaposed with the first external tooth pinion in close proximity and in an eccentric state, and meshes with the internal tooth of the second pin pinion with a tooth surface profile by a cycloid system curve, While engaging the pin pinion, it performs a combined motion consisting of turning displacement and rotation displacement.

  The parallel biaxial constant velocity rotary joint is provided between the first external tooth pinion and the second external tooth pinion, and the second external movement is performed with a one-to-one transmission ratio of the rotational displacement of the combined movement of the first external tooth pinion. Tell the tooth pinion. The output disk is juxtaposed with the second external tooth pinion in close proximity to each other and in an eccentric state. The parallel biaxial constant velocity rotary joint is provided between the second external tooth pinion and the output disk, and transmits the rotational displacement of the combined movement of the second external tooth pinion to the output disk at a transmission ratio of 1: 1.

  Each of the first pinion teeth of the first external tooth pinion is in contact with the inner teeth of the first pin pinion by meshing to set a first collective force point where tangential normal lines forming a pressure angle intersect at one point. Each of the second pinion teeth of the second external tooth pinion is in contact with the inner teeth of the second pin pinion by meshing to set a second collective force point where tangential normal lines forming a pressure angle intersect at one point. The distance from the eccentric position of the first external tooth pinion to the first collective force point is made equal to the distance from the eccentric position of the second external tooth pinion to the second collective force point.

  In this case, with the rotation input of the first external tooth pinion, the first external tooth pinion engages with the first pin pinion and performs a combined motion including rotational displacement and turning displacement. The combined movement of the first external tooth pinion is transmitted to the second external tooth pinion as a rotational displacement by a parallel biaxial constant velocity rotary joint at a transmission ratio of 1: 1. The second external tooth pinion to which the rotation displacement is transmitted performs a combined motion while meshing with the second pin pinion. This combined motion is transmitted to the output disk at a transmission ratio of 1: 1 as a rotational displacement because the rotational displacement is absorbed by the parallel biaxial constant velocity rotary joint.

  At this time, the rotational displacement of the first external tooth pinion is decelerated based on the wave number ratio between the number of teeth of the first external tooth pinion and the first pin pinion, and further, the second external tooth pinion and the second pin pinion Is decelerated based on the wave number ratio. Thereby, the output disk can be rotated by decelerating the first external tooth pinion in a wide range from small to large.

  During the deceleration operation, the parallel biaxial constant velocity rotary joint ensures that the rotation displacement of the first external tooth pinion is reliably transmitted to the second external tooth pinion and the output disk at a ratio of 1: 1. As a result, the first external tooth pinion, the second external tooth pinion and the output disk do not interfere with each other and do not cause backlash. As a result, no noise vibration is generated, the rotation is stabilized during deceleration, and a highly reliable operation, excellent rotation transmission accuracy and long life can be achieved.

(About claim 7)
The parallel biaxial constant velocity rotary joint provided between the first external tooth pinion and the second external tooth pinion is along the same pitch circle with the first external tooth pinion and the second external tooth pinion facing each other. And a series of circular hole groups each having a radial dimension corresponding to the eccentric state of the first external tooth pinion.

The plurality of rolling ball bodies are arranged so as to be able to roll over the circular hole of the first external tooth pinion and the circular hole of the second external tooth pinion, and a pair of rotational displacements in the combined motion of the first external tooth pinion. It is transmitted to the second external tooth pinion with a transmission ratio of 1.

  The parallel biaxial constant velocity rotary joint provided between the second external tooth pinion and the output disk has a second external tooth pinion along the same pitch circle on the second external tooth pinion and the output disk facing each other. A series of circular hole groups each having a radial dimension corresponding to the eccentric state of each. The plurality of rolling ball bodies are arranged so as to be able to roll over the circular hole of the first external tooth pinion and the circular hole of the output disk, and transmit one-to-one rotation displacement of the combined movement of the first external tooth pinion. Tell the output disc by ratio.

  In this case, the parallel biaxial constant velocity rotary joint is formed with a series of circular hole groups in the first external tooth pinion, the second external tooth pinion and the output disk, respectively, as in the case of claim 5 and is converted into a circular hole. A simple structure providing a moving ball body is sufficient, and it is thin and compact, saving space and reducing costs.

(About claim 8)
Since the first rolling ball and the second rolling ball are made of steel, it is easy to obtain these rolling balls, contributing to a reduction in manufacturing cost.

(About claim 9)
Since the rolling ball body is made of steel, it is easy to obtain the rolling ball body as in claim 8 and contributes to a reduction in manufacturing cost.

  In the multistage speed reducer according to the present invention, a parallel biaxial constant velocity rotary joint capable of transmitting rotation with a 1: 1 transmission ratio is used, and a wide range of speed ratios from a small speed reduction ratio to a large speed reduction ratio can be achieved with a simple configuration. In addition, it can be advantageously realized, noise and vibration are not generated, backlash is removed, the entire rotation is smooth and stable during deceleration, reliable operation, excellent rotation transmission accuracy and long life are achieved.

A first embodiment of the present invention will be described based on FIG. 1 and FIG.
In the multistage reduction gear device 1 shown in FIG. 1A, the first eccentric gear 2 is formed with a relatively small diameter and has a predetermined number of external teeth 2a on the outer periphery.

  The fixed first ring gear 3 is created by an involute system or a cycloid system curve having a tooth surface profile having an internal tooth pitch circle P1. The first ring gear 3 includes inner teeth 3a having a predetermined number of teeth on the inner peripheral portion, and the outer teeth 2a of the first eccentric gear 2 are meshed with the inner teeth 3a as planetary gears. The first eccentric gear 2 is configured to perform a combined motion composed of a rotational displacement and a turning displacement with the rotation of a crank input shaft 4 described later.

The crank input shaft 4 has a first connecting shaft 5 as a central axis, one end of which is fixed to the central portion of the first eccentric gear 2, and the other end is rotatably supported by one end of the first eccentric portion 6. ing.
The input shaft 7 is arranged in parallel with the first connecting shaft 5 and is connected and fixed to the other end of the first eccentric portion 6 in a state of being rotatably supported by a bearing 8.

  The distance between the first connecting shaft 5 and the input shaft 7 in the first eccentric portion 6 indicates the first eccentric amount E1, and the inner tooth pitch circle P1 of the first ring gear 3 and the outer tooth pitch circle of the first eccentric gear 2. It is equal to the effective difference from P2 (P1-P2).

  As shown in FIG. 2A, the first connecting shaft 5 slightly extends to the back side of the first eccentric gear 2 to form a connecting end 5 a, and this connecting end 5 a is connected to one end of the second eccentric portion 9. It is fixed. One end of the second connecting shaft 10 is rotatably fitted to the other end of the second eccentric portion 9. The other end of the second connecting shaft 10 is connected and fixed to the central portion of the second eccentric gear 11. The connecting end 5a, the second eccentric portion 9 and the second connecting shaft 10 constitute a first speed change crankshaft 10A.

  The second eccentric gear 11 has external teeth 11a having a predetermined number of teeth, and is arranged adjacent to the first eccentric gear 2 in a face-to-face state. The second ring gear 12 is juxtaposed with the first ring gear 3 so as to be freely rotatable, has a predetermined number of internal teeth 12a, and the internal teeth 12a are external teeth of the second eccentric gear 11. 11a (see FIG. 1 (a)).

The second ring gear 12 has an output shaft 12A integrally formed at the center. The output shaft 12 </ b> A is disposed coaxially with the input shaft 7 and rotates integrally with the second ring gear 12.
In the central portion of the surface portion where the first eccentric gear 2 and the second eccentric gear 11 face each other, a first recess portion Es1 and a second recess portion Es2 that are formed in a circle to accommodate the first transmission crankshaft 10A. Is formed.

  The distance between the second connecting shaft 10 and the first connecting shaft 5 in the second eccentric portion 9 indicates the second eccentric amount E2, and the internal tooth pitch circle P4 of the second ring gear 12 and the external teeth of the second eccentric gear 11 It is equal to the effective difference (P4−P3) from the pitch circle P3. Further, the internal tooth pitch circle P1 of the first ring gear 3 and the internal tooth pitch circle P4 of the second ring gear 12 are set to be equal (P1 = P4).

Between the first eccentric gear 2 and the second eccentric gear 11, there is provided a parallel biaxial constant velocity rotary joint 13 that transmits the rotational displacement of the first eccentric gear 2 to the second eccentric gear 11 with a transmission ratio of 1: 1. It has been.
As shown in FIGS. 2A and 2B, the parallel biaxial constant velocity rotary joint 13 has the same pitch on the outer surface 2A of the first eccentric gear 2 and the outer surface 11A of the second eccentric gear 11 facing each other. It has a series of circular hole groups 14 and 15 formed along the circle Pf.
The circular hole group 14 of the first eccentric gear 2 includes a plurality of (for example, six) circular holes 14a formed at equal angular intervals, and the circular hole group 15 of the second eccentric gear 11 includes a plurality of circular holes 14a formed at equal angular intervals. It consists of (for example, six) circular holes 15a.

  A circular rotation transmission body 16 is disposed between the first eccentric gear 2 and the second eccentric gear 11. The rotation transmission body 16 is a short cylinder with a small thickness, and is loosely fitted so as to roll between the circular hole 14a of the first eccentric gear 2 and the circular hole 15a of the second eccentric gear 11, and each of the circular holes 14a, 15a. A gap of an eccentric amount E3 corresponding to the second eccentric amount E2 is made with respect to the inner peripheral surface {see FIG. 2 (b)}. If the distance between the center 11P of the second eccentric gear 11 and the center 10P of the second connecting shaft 10 is the amount of eccentricity E4, the relationship E1 = | E2 (E3) + E4 | is obtained.

  As the crank input shaft 4 rotates, the rotation transmitting body 16 rolls on the inner peripheral surfaces of the circular hole 14a of the first eccentric gear 2 and the circular hole 15a of the second eccentric gear 11, thereby combining the first eccentric gear 2 with each other. The rotational displacement of the motion is transmitted to the second eccentric gear 11 with a transmission ratio of 1: 1.

In the above configuration, as the crank input shaft 4 rotates, the first eccentric gear 2 engages with the first ring gear 3 and performs a combined motion consisting of rotational displacement and turning displacement.
The combined motion of the first eccentric gear 2 is transmitted to the second eccentric gear 11 via the first transmission crankshaft 10A. At this time, the rotation transmission body 16 of the parallel biaxial constant velocity rotary joint 13 rolls on the inner peripheral surfaces of the circular holes 14a and 15a, so that the rotational displacement of the combined motion of the first eccentric gear 2 is reduced to a transmission ratio of 1: 1. Is transmitted to the second eccentric gear 11, and the second eccentric gear 11 performs a combined motion while meshing the outer teeth 11 a with the inner teeth 12 a of the second ring gear 12. Since the swivel displacement is absorbed in the combined motion, only the rotation displacement is transmitted to the second ring gear 12 to rotate the output shaft 12A together with the second ring gear 12.

  At this time, the rotational displacement of the first eccentric gear 2 is divided by the ratio of the number of external teeth of the second eccentric gear 11 and the number of internal teeth of the second ring gear 12, so that the first eccentric gear 2 is greatly reduced from a small width. Can slow down over a wide range. That is, the reduction ratio can be set at a reduction ratio depending on the number of teeth of the first eccentric gear 2, the first ring gear 3, the second eccentric gear 11, and the second ring gear 12, so that a large reduction speed can be obtained from a small reduction ratio. A wide range of speed ratios can be achieved.

Incidentally, if the first eccentric gear 2 has 80 teeth, the first ring gear 3 has 90 teeth, the second eccentric gear 11 has 70 teeth, and the second ring gear 12 has 80 teeth, the reduction ratio R is as follows: It can be calculated as follows.
R = 1 − {(70 × 90) / (80 × 80)}
= 1/64
Therefore, while realizing a wide range of speed ratios, a simple configuration in which the parallel biaxial constant velocity rotary joint 13 is provided between the first eccentric gear 2 and the second eccentric gear 11 is sufficient, and the manufacturing cost can be reduced. This is advantageous for mass production. Note that the number of teeth of each of the first eccentric gear 2, the first ring gear 3, the second eccentric gear 11, and the second ring gear 12 is exemplary, and therefore does not necessarily match the mode of FIGS. .

  During the deceleration operation, the parallel biaxial constant velocity rotary joint 13 reliably transmits the rotational displacement of the combined motion of the first eccentric gear 2 to the second eccentric gear 11 with a transmission ratio of 1: 1. For this reason, the second eccentric gear 11 does not interfere with the second ring gear 12 and meshes securely in a normal state, no noise vibration is generated, the entire rotation is smooth and stable during deceleration, and the reliability is high. Operation, excellent rotation transmission accuracy and long life can be achieved.

FIG. 3A shows a second embodiment of the present invention.
In the second embodiment, an Oldham joint 13S is used instead of the parallel biaxial constant velocity rotary joint 13 including the rotation transmission body 16, the circular hole 14a of the first eccentric gear 2, and the circular hole 15a of the second eccentric gear 11 in the first embodiment. Is used. The Oldham joint 13S belongs to the category of the parallel biaxial constant velocity rotary joint in the present invention.

  The Oldham coupling 13S includes a sliding ring 13e having four sliding contact grooves 13a, 13b, 13c, and 13d formed by notching at equal angular intervals of 90 degrees on both inner and outer side surfaces. The sliding contact grooves 13a and 13b are opposed to each other in the radial direction on the left side surface of the sliding ring 13e, and the sliding contact grooves 13c and 13d are opposed to each other in the radial direction on the right side surface of the sliding ring 13e.

  On the outer surface 2A of the first eccentric gear 2, sliding blocks 13f and 13g are formed so as to correspond to the sliding contact grooves 13a and 13b and are slidably fitted in the radial direction indicated by the arrow N. On the outer surface 11A of the second eccentric gear 11, sliding blocks 13h and 13i are formed so as to correspond to the sliding contact grooves 13c and 13d and are slidably fitted in the radial direction indicated by the arrow M.

  When the rotational input of the first eccentric gear 2 acts on the second eccentric gear 11 via the first transmission crankshaft 10A, the sliding ring 13e moves in the direction of arrow N according to the eccentricity E2 of the first transmission crankshaft 10A. Rotational displacement is performed with a turning displacement in a direction that combines the displacement in the direction of arrow M and the displacement in the direction of the arrow M, and only the rotational displacement is transmitted to the second eccentric gear 11 at a transmission ratio of 1: 1.

FIG. 3B shows a third embodiment of the present invention.
In Example 3, the place where the sliding block and the sliding contact groove are formed in the Oldham coupling 13S is reversed from that in Example 2. That is, sliding blocks 13f and 13g are formed on the left side surface of the sliding ring 13e, and sliding blocks 13h and 13i are provided on the right side surface of the sliding ring 13e.

  A thin flat ring 13j is integrally provided on the outer surface 2A of the first eccentric gear 2, and a thin flat ring 13k is also integrally provided on the outer surface 11A of the second eccentric gear 11. Sliding contact grooves 13a and 13b are formed in the flat ring 13j, and sliding contact grooves 13c and 13d are formed in the flat ring 13k. The sliding blocks 13f and 13g are slidably fitted in the sliding contact grooves 13a and 13b, and the sliding blocks 13h and 13i are slidably fitted in the sliding contact grooves 13c and 13d.

  When the rotational input of the first eccentric gear 2 acts on the second eccentric gear 11 via the first transmission crankshaft 10A, the sliding ring 13e is displaced in the direction of the arrow N and the direction of the arrow M, as in the second embodiment. The rotation displacement is performed with the turning displacement in the direction in which the above displacement is combined, and only the rotation displacement is transmitted to the second eccentric gear 11 at a transmission ratio of 1: 1.

FIG. 4 shows a fourth embodiment of the present invention.
The fourth embodiment differs from the first embodiment in that a pin 13p is provided as a parallel biaxial constant velocity rotary joint 13T in place of the rotation hole 16a and the circular hole 14a of the first eccentric gear 2. The pin 13p is fixed to the first eccentric gear 2 instead of the circular hole 14a, and the diameter dimension Dp of the pin 13p is set smaller than the diameter dimension Dq of the circular hole 15a, and the difference in diameter between the two (Dq−Dp ) Is made equal to the eccentric amount E2 of the first transmission crankshaft 10A.
When the rotational input of the first eccentric gear 2 acts on the second eccentric gear 11 via the first transmission crankshaft 10A, the pin 13p performs a circular motion while slidingly contacting the outer peripheral wall surface of the circular hole 15a. For this reason, the first eccentric gear 2 performs a combined motion consisting of a turning displacement and a rotation displacement, and transmits only the rotation displacement to the second eccentric gear 11 with a transmission ratio of 1: 1.

FIG. 5 shows a fifth embodiment of the present invention.
In the fifth embodiment, a cycloid external pinion 27 is used instead of the first ring gear 3 and the second ring gear 12 in the first embodiment, and instead of the first eccentric gear 2 and the second eccentric gear 11, a pin is used. A pinion 28 is used. The external tooth pinion 27 meshes the pinion teeth 27a with the cylindrical pin 28a of the pin pinion 28 in an inscribed state {see FIGS. 5A and 5B}.

The external tooth pinion 27 for the first ring gear 3 and the external tooth pinion 27 for the second ring gear 12 are different in the number of teeth of the pinion teeth 27a, but the number of teeth can be set variously. It was kept only to show the form.
Also, the pin pinion 28 for the first eccentric gear 2 and the pin pinion 28 for the second eccentric gear 11 are different in the number of teeth of the cylindrical pin 28a, but the number of teeth can be set variously. Only the form of the pinion 28 is shown.
In addition, when the external pinion 27 is displaced positively or negatively, the meshing pitch circle in the external tooth pinion for the first ring gear 3 and the external tooth pinion for the second ring gear 12 are necessary in order to achieve a deceleration operation. It is necessary to set the mesh pitch circle in the same. The same applies to Example 6 described later.

FIG. 6 shows Embodiment 6 of the present invention.
In the sixth embodiment, a cycloid internal pinion 31 is used instead of the first ring gear 3 and the second ring gear 12 in the first embodiment, and instead of the first eccentric gear 2 and the second eccentric gear 11, a pin is used. A pinion 32 is used. The internal tooth pinion 31 meshes the pinion teeth 31a with the cylindrical pin 32a of the pin pinion 32 in an inscribed state.

The number of teeth of the pinion teeth 31a is different between the internal tooth pinion 31 for the first ring gear 3 and the internal tooth pinion 31 for the second ring gear 12, but the number of teeth can be set variously. It was kept only to show the form.
Also, the pin pinion 32 for the first eccentric gear 2 and the pin pinion 32 for the second eccentric gear 11 are different in the number of teeth of the cylindrical pin 32a, but the number of teeth can be set variously. Only the form of the pinion 32 is shown.

7 to 9 and FIGS. 11 to 13 show Embodiment 7 of the present invention.
In the multistage speed reducer 35 of the fifth embodiment, as shown in FIG. 7, a fixed disk 36, a first speed change disk 37, a plurality of first rolling balls 38, a second speed change disk 39, and a parallel biaxial constant velocity rotary joint 40A. The output disk 41A and the second rolling ball 42 are arranged in close proximity to each other.

  The fixed disk 36 has a through-hole 36a in the center, is formed in a circumferential direction along the first pitch circle Q1 on one side, and is a first curve of a cycloid system (for example, epicycloid) having a substantially arc-shaped cross section. A tooth gap 43 is provided. The first curved tooth groove 43 has, for example, 22 wave numbers.

  The first speed change disk 37 is formed with a through hole 37a at the center, and is disposed close to the fixed disk 36 so as to face an eccentric state with a first eccentric amount e1. A cycloid system that is formed in a circumferential direction along a second pitch circle Q2 that is the same as the first pitch circle Q1 in the surface portion corresponding to the first curved tooth groove 43 of the first transmission disc 37 and has a substantially arc-shaped cross section. The second curved tooth groove 44 is provided. The second curved tooth groove 44 has 24 wave numbers and two wave number differences from the first curved tooth groove 43.

  The plurality of first rolling balls 38 are made of, for example, steel (steel material), and are arranged over the first curved tooth groove 43 of the fixed disk 36 and the second curved tooth groove 44 of the first transmission disk 37. As the input shaft 36 </ b> A, which will be described later, rotates, the first speed change disk 37 performs a combined motion including rotational displacement and turning displacement with respect to the fixed disk 36.

  The second speed change disk 39 is formed with a through hole 39a at the center, faces the first speed change disk 37 with a second eccentric amount e2 in an eccentric state, and a third pitch circle Q3 on the opposite side to the facing side. A cycloid-type third curved tooth groove 45 formed in the circumferential direction along the top and having a substantially circular arc cross section is provided. The third curved tooth gap 45 has, for example, 22 wave numbers. An input shaft 36A provided at the center of the fixed disk 36 is inserted through the through holes 39a, 37a, 36a and protrudes to the right in the figure.

  Between the first transmission disk 37 and the second transmission disk 39, a ball-type parallel two-axis that transmits the rotational displacement of the combined movement of the first transmission disk 37 to the second transmission disk 39 at a transmission ratio of 1: 1. A constant velocity rotary joint 46 is provided.

  In the parallel biaxial constant velocity rotary joint 46, a series of circular hole groups 40, 41 are formed on the first transmission disk 37 and the second transmission disk 39 on the opposite surfaces facing each other along the same pitch circle Qp. Is formed in the direction. The circular hole group 40 of the first speed change disk 37 has a substantially arc shape in cross section and includes a plurality of circular holes 40a, and the circular hole group 41 of the second speed change disk 39 has a shape of a substantially arc shape and includes a plurality of circular holes 41a. Yes. The circular hole 40a and the circular hole 41a have the same diameter, and the diameter difference between the circular hole 40a (41a) and a rolling ball body 47 described later is made equal to the second eccentric amount e2.

  A plurality of rolling ball bodies 47 constitute a parallel biaxial constant velocity rotary joint 46, and are arranged so as to roll over a circular hole 40a of the first transmission disk 37 and a circular hole 41a of the second transmission disk 39. {See FIG. 7B}. Along with the rotation of the input shaft 36A, the rotational displacement of the combined movement of the first transmission disk 37 is transmitted to the second transmission disk 39 at a transmission ratio of 1: 1.

  The output disk 41A is disposed in a close proximity to the second transmission disk 39 so as to face the eccentric state with a third eccentric amount e3. On the surface portion of the output disk 41A facing the third curved tooth groove 45, a cycloidal fourth curved tooth groove 48 formed in the circumferential direction along a fourth pitch circle Q4 having the same dimensions as the third pitch circle Q3. Have

  The fourth curved tooth groove 48 has a substantially arc shape in cross section, and has a wave number set to, for example, 20, and has two wave number differences from the third curved tooth groove 45. An output shaft 49 that protrudes on the opposite side of the input shaft 36A is coaxially formed at the center of the output disk 41A. Therefore, if the third eccentric amount e3 is positive and the first eccentric amount e1 and the second eccentric amount e2 are negative, the third eccentric amount e3 is equal to the sum of the first eccentric amount e1 and the second eccentric amount e2. (E3 = | e1 + e2 |).

  The plurality of second rolling balls 42 are arranged over the third curved tooth groove 45 and the fourth curved tooth groove 48, and when the second speed change disk 39 performs the combined motion with respect to the output disk 41A, the second rolling ball 42 is provided. Of the combined motion of the speed change disc 39, the turning motion is absorbed and only the rotational displacement is output from the output disc 41A.

  Here, as shown in FIG. 8A, the pressure angle formed by each of the first rolling balls 38 meshing with the wave teeth 43w of the first curved tooth groove 43 of the fixed disk 36 at the time of research, trial manufacture, and experiment. It has been found that the normal line Tn of the meshing tangent line T1 serving as the reference value of ω1 intersects at one point as a collective power point. Collective force points are similarly obtained for the second curved tooth groove 44 of the first transmission disk 37 and the third curved tooth groove 45 of the second transmission disk 39.

  As a representative example, FIG. 8B shows the first collective force point Px1 of the first curved tooth groove 43 in the fixed disk 36, and FIG. 8C shows the second collective force point Px2 of the fourth curved tooth groove 48 in the output disk 41A. ). Each position of the first collective force point Px1 and the second collective force point Px2 is located inside the fixed disk 36 and the output disk 41A, unlike the case of Example 7 described later.

  At this time, the distance from the first eccentric position Ep1 of the first eccentric amount e1 to the first collective force point Px1 is the first effective diameter L1, and the distance from the second eccentric position Ep2 of the second eccentric amount e2 to the second collective force point Px2 When the distance is the second effective diameter L2, the first effective diameter L1 and the second effective diameter L2 are set to be equal.

  Further, the second curved tooth groove 44 of the first transmission disk 37, the third curved tooth groove 45 of the second transmission disk 39, and the fourth curved tooth groove 48 of the output disk 41A are similarly from the eccentric position to the collective force point. The effective diameter is set to be the same as the first effective diameter L1 or the second effective diameter L2. That is, the first curved tooth groove 43 of the fixed disk 36, the second curved tooth groove 44 of the first transmission disk 37, the third curved tooth groove 45 of the second transmission disk 39, and the fourth curved tooth groove 48 of the output disk 41A. The obtained effective diameters are set to be equal to each other.

  Incidentally, if the first pitch circle Q1 of the fixed disk 36 and the fourth pitch circle Q4 of the output disk 41A are 60.41 mm, as shown in FIGS. 8B, 8C, and 9B, The first eccentric amount e1 is set to 0.91304462 mm, the third eccentric amount e3 is set to 1.00000000 mm, and the first effective diameter L1 and the second effective diameter L2 are set to 21.15157975 mm.

In adjusting the first effective diameter L1 and the second effective diameter L2 equally, the first pitch circle Q1 and the fourth pitch circle Q4 are changed, or the first curved tooth groove 43 and the fourth curved tooth groove 48 are changed. This is done by changing the dislocation amount or cycloid coefficient (= 1-dislocation amount).
Regarding the dislocation amount, the first collective force point Px1 (second collective force point Px2) extends along the radial direction if the wave tooth of the first curved tooth groove 43 (fourth curved tooth groove 48) is rounded down by a negative dislocation amount. Since it is displaced to the center, the length of the first effective diameter L1 (second effective diameter L2) can be adjusted by increasing or decreasing the amount of dislocation. Similarly, the effective diameter of the second curved tooth groove 44 of the first transmission disk 37 and the third curved tooth groove 45 of the second transmission disk 39 can be adjusted.

  In the above-described configuration, as the first speed change disk 37 rolls the first rolling ball 38 against the first curved tooth groove 43 and the second curved tooth groove 44 in accordance with the rotation input to the input shaft 36A, the rotation displacement and the turning Perform compound motion including displacement. The combined motion of the first speed change disk 37 is transmitted to the second speed change disk 39 at a transmission ratio of 1: 1 via the parallel biaxial constant velocity rotary joint 40A.

That is, when the first speed change disk 37 performs a combined motion, the rolling ball body 47 of the parallel biaxial constant velocity rotary joint 40A rolls in the circular holes 40a and 41a, whereby the first speed change disk 37 has a combined motion. Among them, the rotation displacement is transmitted to the second speed change disk 39 as it is.
The second speed change disk 39 to which the combined movement is transmitted absorbs the turning displacement by performing the combined movement while rolling the second rolling ball 42 with respect to the third curved tooth groove 45 and the fourth curved tooth groove 48. Only the rotation displacement is transmitted to the output disk 41A, and the output shaft 49 is rotated.

  At this time, the rotational displacement of the first speed change disc 37 is decelerated based on the wave number ratio between the first curved tooth groove 43 and the second curved tooth groove 44, and further, the third curved tooth groove 45 and the fourth curve. Deceleration is performed based on the wave number ratio with the tooth gap 48. Accordingly, the output disk 41A can be rotated by decelerating the first speed change disk 37 over a wide range from small to large.

Here, the fixed disk 36 (first curved tooth groove 43) has 22 wave numbers, the first transmission disk 37 (second curved tooth groove 44) has 24 wave numbers, and the second transmission disk 39 (third curved tooth groove). 45) has 22 wave numbers and the output disk 41A (fourth curve tooth groove 48) has 20 wave numbers, the reduction ratio Rp is calculated as follows.
Rp = 1− {22 × 22 / (24 × 20)}
= 1- (484/480)
= -1 / 120
In this regard, in FIG. 9A, the wave number of the first curved tooth groove 43 is A, the wave number of the second curved tooth groove 44 is B, the wave number of the third curved tooth groove 45 is C, and the wave number of the fourth curved tooth groove 48 is. The wave number is represented as D in the table of FIG. 9C, and the reduction ratio Rp can be obtained by the following equation.
Rp = 1− {A × C / (B × D)}

That is, since the reduction ratio can be set at a reduction ratio depending on each wave number of Rp, the first transmission disk 37 and the second transmission disk 39, a wide speed ratio can be realized from a small reduction ratio to a large reduction ratio.
While realizing a wide range of speed ratios, a simple configuration in which the parallel biaxial constant velocity rotary joint 46 is provided between the first transmission disk 37 and the second transmission disk 39 is sufficient, and the production cost can be suppressed and mass production can be achieved. This is advantageous.

  During the deceleration operation, the parallel biaxial constant velocity rotary joint 46 reliably transmits the rotational displacement of the first movement disk 37 to the second transmission disk 39 at a ratio of 1: 1. For this reason, the second rolling ball 42 reliably meshes with the first curved tooth groove 43 and the second curved tooth groove 44 without interference and rolls smoothly.

  As a result, backlash is eliminated, noise vibration is not generated, rotation is stabilized during deceleration, reliable operation, excellent rotation transmission accuracy, and long life can be achieved.

  FIGS. 9D and 9E show a modification of the circular hole 40a in the fifth embodiment, which is formed in a donut-shaped recess 40B having a semicircular cross section centered on the central protrusion 40C. Has been. The diameter Td of the rolling ball body 47 and the arc diameter Rd of the hollow portion 40B are made substantially the same so that the rolling ball body 47 fits in the hollow portion 40B so as to be able to roll.

  FIG. 10 shows a multistage speed reducer 50 manufactured at the beginning of the research, experiment, and trial production process. The second speed change disk 39 is fixed to the fixed disk 36 without using the first speed change disk 37 and the parallel biaxial constant velocity rotary joint 46. And the output disk 41A. A second curved tooth groove 44 is formed in the second speed change disk 39 in place of the circular hole group 41.

  In this case, the first rolling ball 38 interferes with the first curved tooth groove 43 and the second curved tooth groove 44, and the second rolling ball against the third curved tooth groove 45 and the fourth curved tooth groove 48. Thus, there is a disadvantage that the rolling state of the first rolling ball 38 and the second rolling ball 42 is not smooth.

  As it became clear after repeating and continuing research, experiment and trial production, in order to realize a high precision and precise multistage reduction gear 35 by smooth rotation, a parallel biaxial constant velocity rotary joint 46 is provided, As described above, as described above, it is necessary to obtain the collective force points Px1 and Px2 in the first curved tooth groove 43 of the fixed disk 36 and the fourth curved tooth groove 48 of the output disk 41A and set the effective diameters L1 and L2 to be equal. (See FIG. 8).

That is, the first curved tooth groove 43 of the fixed disk 36, the second curved tooth groove 44 of the first transmission disk 37, the third curved tooth groove 45 of the second transmission disk 39, and the fourth curved tooth groove 48 of the output disk 41A. The obtained effective diameters are set to be equal to each other.
In view of the first embodiment, this requirement is considered to correspond to the case where the internal tooth pitch circle P1 of the first ring gear 3 and the internal tooth pitch circle P4 of the second ring gear 12 are set equal.
From this point of view, the collective force points Px1 and Px2 can be said to be points on the virtual meshing pitch circle, assuming that the collective force points Px1 and Px2 can be converted into the meshing position of the curved tooth groove of the disk and the rolling ball.

11 shows a fixed disk 36, a first speed change disk 37, a plurality of first rolling balls 38, a second speed change disk 39, a parallel biaxial constant velocity rotary joint 46, an output disk 41A and a second rolling ball 42. In addition, a longitudinal sectional view embodying the multistage reduction gear 35 is shown.
The side of the input shaft 36A where the first eccentric amount e1, the second eccentric amount e2 and the third eccentric amount e3 are present is oriented in one direction (the surface side of the drawing), and the input shaft 36A and the output shaft 49 with respect to the central axis Cp. The positional deviation amount is the total eccentric amount Ep4.

  The right end portion 36B of the input shaft 36A is rotatably supported by a first ball bearing 52 provided on the housing 51, and the third intermediate portion 36E at the left end portion is rotatably supported by a second ball bearing 54. . The first intermediate portion 36C of the input shaft 36A supports the first transmission disc 37 by the first roller bearing 53 so as to be able to perform the combined motion with the first eccentric amount e1 and the second eccentric amount e2, and the second intermediate portion 36D The two speed change disc 39 is supported by the second roller bearing 53a so as to be able to perform the combined motion with the second eccentric amount e2 and the third eccentric amount e3.

  In the output disk 41A, the third intermediate portion 36E coaxial with the shaft core is supported by the second ball bearing 54, while the dish-shaped tapered portion 41b is rotatably supported by the third ball bearing 55 and the thrust bearing 56. . The tapered portion 41 b extends integrally toward the output shaft 49 at the left end, and a midway portion is supported by the fourth ball bearing 57.

  Since the side where the first eccentric amount e1, the second eccentric amount e2 and the third eccentric amount e3 exist in the input shaft 36A is oriented in one direction, the balance weight 58 is attached to the input shaft 36A, and the input shaft 36A The rotation is smoothed by the flywheel effect during rotation.

  In the multistage reduction gear 35 of FIG. 12, the side where the first eccentricity e1 and the second eccentricity e2 exist and the side where the third eccentricity e3 exists of the input shaft 36A in FIG. 11 have a phase difference of 180 degrees. The juxtaposed state is shown. The eccentricity direction of the first eccentricity e1 and the second eccentricity e2 with respect to the center axis Cp of the output shaft 49 is directed to the lower side of the paper as the sum eccentricity Es, and the eccentricity direction of the third eccentricity e3 is set as the single eccentricity Et above the paper. Is aimed at.

  In this case, since the sum eccentricity Es and the single eccentricity Et are opposed to each other with a phase difference of 180 degrees, a balance can be ensured at the time of rotation, and there is no need to mount the balance weight 58 on the input shaft 36A as a flywheel.

13, the wave number of the fixed disk 36 (first curved tooth groove 43), the wave number of the first transmission disk 37 (second curved tooth groove 44), and the second transmission disk 39 (first gear). The wave number of the third curved tooth groove 45) and the wave number of the output disk 41A (fourth curved tooth groove 48) are set to be small to achieve a relatively small reduction ratio. That is, if the above-described disk wave numbers are 9, 10, 8, and 9, respectively, the reduction ratio Rc is calculated by the following procedure.
Rc = 1− {9 × 8 / (9 × 10)}
= 1-72 / 90
= 1/5

  14 and 15 show an eighth embodiment of the present invention. In the eighth embodiment, a hypocycloid planetary gear mechanism is provided as the multistage reduction gear 61 in the configuration of the seventh embodiment shown in FIG. In this multistage reduction gear 61, as shown in FIGS. 14A and 14B, a first external tooth pinion 62 (external tooth trochoid pinion) having, for example, 45 teeth is provided, and the number of teeth is, for example, 40. A second external tooth pinion 63 (external tooth trochoid pinion) is provided.

  The first external tooth pinion 62 is rotatably supported by the first roller bearing 53 on the right end portion 36B of the input shaft 36A, and the outer peripheral first pinion tooth 62a is a cylindrical pin tooth that is an internal tooth of the first pin pinion 64. 64a (see FIG. 15A).

  As shown in FIG. 15B, the first pin and pinion 64 can rotate, for example, 46 cylindrical pin teeth 64a at equal angular intervals in the circumferential direction by a needle shaft 65 between cage-shaped rings 65a and 65b. Installed.

  The second external tooth pinion 63 is rotatably supported by the first intermediate portion 36C of the input shaft 36A by a second roller bearing 53a, and the outer peripheral second pinion tooth 63a is a cylinder that is an internal tooth of the second pin pinion 66. The pin teeth 66a are engaged with each other. As shown in FIG. 15B, the second pin pinion 66 can rotate, for example, 41 cylindrical pin teeth 66a at equal angular intervals in the circumferential direction by a needle shaft 67 between cage-shaped rings 65b and 65c. Installed.

As a pre-process for attaching the first external tooth pinion 62 and the second external tooth pinion 63 to the input shaft 36A, a first collective force point Px3 of the first external tooth pinion 62 and a second collective force point Px4 of the second external tooth pinion 63 are illustrated. 8 is obtained in the same manner as in Example 7. Unlike the seventh embodiment shown in FIG. 8, the positions of the first collective force point Px3 and the second collective force point Px4 are located outside the first external tooth pinion 62 and the second external tooth pinion 63.
After setting the eccentric amount Ep5 from the center line PL1 of the first external tooth pinion 62 and the eccentric amount Ep6 from the center line PL2 of the second external tooth pinion 63, the distance between the eccentric position Er1 of the eccentric amount Ep5 and the collective force point Px3 An effective diameter Lx corresponding to is obtained.

  An effective diameter Ly corresponding to the distance between the eccentric position Er2 of the eccentric amount Ep6 in the second external tooth pinion 63 and the collective force point Px4 is obtained. By adjusting the dislocation amounts of the first external tooth pinion 62 and the second external tooth pinion 63, the positions of the first collective force point Px3 and the second collective force point Px4 are changed, and the effective diameter from the first collective force point Px3 is changed. Lx is made equal to the effective diameter Ly from the second collective force point Px4.

As an example, the pitch radius Rf of the first external tooth pinion 62 is 49.29595751 mm, the pitch radius Rg of the first pin pinion 64 is 50.56901906 mm, and the difference between both pitch radii is 1.273323955 mm as the eccentric amount Ep5.
The pitch circle Rh of the second external tooth pinion 63 is 49.162218663 mm, the pitch circle Ri of the second pin pinion 66 is 50.59069929 mm, and the difference between both pitch radii is 1.428512266 mm as the eccentric amount Ep6.

The dislocation amount S1 of the first external tooth pinion 62 is 8.000000000 mm, the number N1 of the first pinion teeth 62a is 45, and the number M1 of the cylindrical pin teeth 64a in the first pinion 64 is 46.
The dislocation amount S2 of the second external tooth pinion 63 is 7.97883970 mm, the number N2 of the second pinion teeth 63a is 40, and the number M2 of the cylindrical pin teeth 66a in the second pinion 66 is 41. In this case, the reduction ratio Rt in the multistage reduction gear 61 is specifically obtained by Rt = 1− {M1 × N2 / (N1 × M2)} as calculated later.

  As shown in FIG. 15, the first external tooth pinion 62 and the second external tooth pinion 63 are juxtaposed in close proximity to each other, and between them, similar to the parallel biaxial constant velocity rotary joint 46 of the fifth embodiment. A ball-type parallel biaxial constant velocity rotary joint 68 is provided. In the first external tooth pinion 62, a plurality of (for example, six) circular holes 69 are formed along the predetermined pitch circle Pe1 with a constant diameter dimension Dp1 at equal angular intervals. The second external tooth pinion 63 is also formed with the same number of circular holes 70 as the circular holes 69 along the pitch circle Pe2 that is the same as the pitch circle Pe1 at equal angular intervals. The number and the diameter dimension Dp1 of the circular holes 69 may be the same as or different from the number and the diameter dimension Dp2 of the circular holes 70, and can be set as desired depending on the use situation.

  In the circular hole 69 of the first external tooth pinion 62 and the circular hole 70 of the second external tooth pinion 63, for example, a rolling ball body 71 formed of steel moves in the circumferential direction around the inner peripheral part of both the circular holes 69, 70. It is arranged to roll on. The rolling ball body 71 is set to be smaller in diameter than the circular holes 69 and 70, and the difference between the diameter Dp 3 of the rolling ball body 71 and the diameter Dp 1 of the circular hole 69 is determined as the eccentricity of the first external pinion 62. The difference between the diameter Dp3 of the rolling ball body 71 and the diameter Dp2 of the circular hole 70 is made equal to the eccentric amount Ep6 of the second external tooth pinion 63. A parallel biaxial constant velocity rotary joint 68 is constituted by the circular hole 69 of the first external tooth pinion 62, the circular hole 70 of the second external tooth pinion 63, and the rolling ball body 71.

  A ball-type parallel biaxial constant velocity rotary joint 72 similar to the parallel biaxial constant velocity rotary joint 68 is also provided between the second external tooth pinion 63 and the fixed disk 36 that are juxtaposed in close proximity to each other. The parallel biaxial constant velocity rotary joint 72 is also composed of a circular hole 73 of the second external tooth pinion 63, a circular hole 74 of the fixed disk 36, and a rolling ball body 75 made of steel. The diameter difference between the rolling ball body 75 and the circular hole 74 is made equal to the eccentric amount Ep6 of the second external tooth pinion 63.

When the input shaft 36A is rotated clockwise in this state, the first external pinion 62 is fitted into the right end portion 36B of the input shaft 36A via the first roller bearing 53. A combined motion consisting of rotational displacement and rotational displacement is performed while meshing with the cylindrical pin teeth 64a.
Along with this, the rolling ball body 71 of the parallel biaxial constant velocity rotary joint 68 moves between the inner peripheral part of the circular hole 69 of the first external tooth pinion 62 and the circular hole 70 of the second external tooth pinion 63. It rolls and absorbs the rotational displacement of the first external tooth pinion 62 and transmits only the rotational displacement to the second external tooth pinion 63 at a transmission ratio of 1: 1.

  Since the second external tooth pinion 63 is fitted to the first intermediate portion 36C of the input shaft 36A via the second roller bearing 53a, the second external tooth pinion 63 is rotated and displaced while meshing with the cylindrical pin teeth 66a of the second pin pinion 66. Performs a combined motion consisting of rotational displacement. Along with this, the rolling ball body 75 of the parallel biaxial constant velocity rotary joint 72 rolls on the inner peripheral part of the circular hole 73 of the second external tooth pinion 63 and the inner peripheral part of the circular hole 74 of the output disk 41A. 2 The rotational displacement of the external tooth pinion 63 is absorbed, and only the rotational displacement is transmitted to the output disk 41A at a transmission ratio of 1: 1.

  Since the third intermediate portion 36E coaxial with the input shaft 36A is fitted through the second ball bearing 54, the output disk 41A rotates in the clockwise direction in response to the rotation displacement of the second external tooth pinion 63. .

  At this time, the first external pinion 62 is decelerated by the division ratio between the number N1 of the first pinion teeth 62a and the number M1 of the cylindrical pin teeth 64a of the first pinion 64, and then the second external teeth The speed is reduced by a division ratio between the number N2 of the second pinion teeth 63a in the tooth pinion 63 and the number M2 of the cylindrical pin teeth 66a in the second pinion 66.

  That is, the number of teeth N1 of the first pinion teeth 62a is 45, the number of teeth M1 of the cylindrical pin teeth 64a is 46, the number of teeth N2 of the second pinion teeth 63a is 40, and the number of teeth M2 of the cylindrical pin teeth 66a is Since the number is 41, the reduction ratio Rt in the multistage reduction gear 61 becomes (−1/369) by 1− {46 × 40 / (45 × 41)}, and an extremely small reduction ratio Rt can be obtained.

  While realizing a wide range of speed ratios from a small reduction ratio to a large reduction ratio, a ball-type parallel biaxial constant velocity rotary joint 68 is provided between the first external tooth pinion 62 and the second external tooth pinion 63, and the same The parallel biaxial constant velocity rotary joint 72 is simply provided between the second external tooth pinion 63 and the output disk 41A, which is advantageous for mass production with reduced manufacturing costs.

  During the deceleration operation, the parallel biaxial constant-velocity joint 68 transmits the rotational displacement of the combined movement of the first external pinion 62 to the second external pinion 63 with a transmission ratio of 1: 1, and parallel biaxial constant-speed rotation. The joint 72 transmits the rotational displacement of the combined movement of the second external tooth pinion 63 to the output disk 41A at a transmission ratio of 1: 1.

  For this reason, the rolling ball body 71 does not interfere with the first external tooth pinion 62 and the second external tooth pinion 63, and the rolling ball body 75 does not interfere with the output disk 41A. Engagement is ensured in a normal state without occurrence, no noise vibration is generated, the entire rotation is smooth and stable at the time of deceleration, reliable operation, excellent rotation transmission accuracy and long life can be achieved.

  Between the second external tooth pinion 63 and the output disk 41A, a third pin pinion having a number of teeth different from the number of teeth M1, M2 and a third external tooth pinion having a number of teeth different from the number of teeth N1, N2 (both (Not shown) are arranged side by side, a parallel biaxial constant velocity rotary joint (not shown) is provided between the third external tooth pinion and the second external tooth pinion 63, and the third external tooth pinion and the output disk 41A are provided. Between them, another parallel biaxial constant velocity rotary joint (not shown) may be provided.

In this case, the rotation of the input shaft 36A is reduced in three stages by the second external tooth pinion 63 and the third external tooth pinion, in addition to the two-stage speed reduction by the first external tooth pinion 62 and the second external tooth pinion 63. Is done.
That is, the rotational displacement of the first external tooth pinion 62 is decelerated to two-stage deceleration, and then the number of teeth of the third pinion tooth of the third external tooth pinion and the number of teeth of the cylindrical pin tooth of the third pin pinion Dividing based on the division ratio.

As a result, the rotational displacement of the first external pinion 62 can be reduced over a wide range from small to large, and a wider speed ratio can be realized from a small reduction ratio to a much larger reduction ratio. Can be made.
In order to realize an extremely large reduction ratio, in addition to the third external tooth pinion, a large number of external tooth pinions such as the fourth external tooth pinion and the fifth external tooth pinion are connected by a parallel biaxial constant velocity rotary joint. They may be connected alternately and juxtaposed in multiple.
Note that the pitch circle Rf of the first external pinion 62 and the pitch circle Rh of the second external pinion 63 may be the same or different, and the pitch circle Rg of the first pin pinion 64 and the second pin pinion 66 may be different. The pitch circle Ri may not be the same and may be different.

(A) The number of teeth of the first eccentric gear 2, the first ring gear 3, the second eccentric gear 11, and the second ring gear 12 in the first embodiment may be changed as desired according to the application object and the use situation. The same applies to the wave numbers of the fixed disk 36, the first speed change disk 37, the second speed change disk 39, and the output disk 41A in the fifth embodiment.
In theory, the first eccentric gear 2 in the first ring gear 3 and the second eccentric gear 11 in the second ring gear 12 of the first embodiment are theoretically n alternately via the parallel biaxial constant velocity rotary joint. Can be juxtaposed.
Theoretically, the fixed disk 36, the first speed change disk 37, the second speed change disk 39, and the output disk 41A of the fifth embodiment also theoretically have n sets of multiple juxtapositions of the first speed change disk 37 and the second speed change disk 39. Is possible.

(B) The number of teeth N1 of the first pinion teeth 62a of the first external tooth pinion 62 in Example 7, the number of teeth M1 of the cylindrical pin teeth 64a of the first pin pinion 64, and the second pinion teeth of the second external tooth pinion 63 The number of teeth N2 of 63a and the number of teeth M2 of the cylindrical pin teeth 66a of the second pin pinion 66 may also be changed to the necessary numbers.
The set of the first external tooth pinion 62 and the first pin pinion 64 and the set of the second external tooth pinion 63 and the second pin pinion 66 of Example 7 are theoretically connected via a parallel biaxial constant velocity rotary joint. In this way, n pairs can be alternately arranged in parallel.

(C) The first rolling ball 38, the second rolling ball 42, and the rolling ball body 47 in the fifth embodiment are not limited to steel (steel), but are made of soft steel, stainless steel, reinforced ceramic, or various metal alloys. It may be formed. Instead of the ball-type parallel biaxial constant velocity rotary joint 46 of the fifth embodiment, the parallel biaxial constant velocity rotary joint 13 of the rotation transmission body 16 of the first embodiment may be used. Conversely, instead of the parallel biaxial constant velocity rotary joint 13 of the rotation transmission body 16 of the first embodiment, the ball type parallel biaxial constant velocity rotary joint 46 of the fifth embodiment may be used.

(D) The rotation transmission body 16 is not limited to a short cylinder, and the shape can be changed as necessary. As the material of the rotation transmission body 16, a metal material such as steel or a reinforced ceramic can be applied.
(E) The first curved tooth groove 43 of the fixed disk 36, the second curved tooth groove 44 of the first transmission disk 37, the third curved tooth groove 45 of the second transmission disk 39, and the fourth curved tooth groove 48 of the output disk 41A. In addition to the epicycloid system, various curves generated as a locus by the rotation of the object, such as a hypocycloid system, a peritrochoid system, and an epitrochoid system, may be applied.

  In a multistage reduction gear, using a parallel biaxial constant velocity rotary joint capable of transmitting torque with a transmission ratio of 1: 1, a wide range of speed ratios from a small reduction ratio to a large reduction ratio is advantageous in terms of cost with a simple configuration. In addition, there is no generation of noise and vibration, the entire rotation is smooth and stable during deceleration, and highly reliable operation, excellent rotation transmission accuracy and long life are achieved. Although it is small, it can be widely used in the machinery industry through the distribution of related parts as the number of customers who demand production efficiency increases due to the benefit of achieving a highly accurate reduction ratio in a very wide range.

(A) is a disassembled perspective view (Example 1) which shows a multistage speed reducer, (b) is a schematic diagram which shows a multistage speed reducer (Example 1). (A) is a perspective view which shows the parallel biaxial constant velocity rotary joint provided between the 1st eccentric gear and the 2nd eccentric gear, (b) is a longitudinal cross-sectional view of a multistage reduction gear apparatus (Example 1). . (A) is an exploded perspective view (Example 2) which shows an Oldham coupling, (b) is an exploded perspective view which shows another Oldham coupling (Example 3). (Example 4) which is a perspective view which shows the parallel biaxial constant velocity rotary joint comprised by the pin and the circular hole. (A) is the front view (Example 5) which shows the example which applied the internal-tooth pinion to the eccentric gear, and applied the pin pinion to the ring gear, (b) is an expanded partial front view which shows a meshing state (Example) 5). (Example 6) which is the front view which shows the example which applied the external pinion to the eccentric gear and applied the pin pinion to the ring gear. (A) is a disassembled perspective view (Example 7) which shows a multistage reduction gear, (b) is an expanded longitudinal cross-sectional view which follows K1-K1 of (a) (Example 7). (A) is a schematic diagram (Example 7) for showing the normal of the meshing tangent line which becomes the reference value of the pressure angle, (b) is a schematic diagram showing the collective power point in the fixed disk (Example 7), (c) These are the schematic diagrams which show the collective power point in an output disc (Example 7). (A) is a schematic diagram (Example 7) showing a multistage reduction gear, (b) is a schematic diagram showing an eccentric state of the input shaft (Example 7), and (c) is a chart for calculating a reduction ratio ( Examples 7), (d), and (e) are modified examples of the circular holes in Example 7. It is a disassembled perspective view which shows the multistage reduction gear produced at the beginning of research, experiment, and trial manufacture process for comparison (comparison figure). (Example 7) which is the longitudinal cross-sectional view of the multistage speed reducer comprised by having assembled the 1st speed change disk and the 2nd speed change disk with the same phase. (Example 7) which is the longitudinal cross-sectional view of the multistage speed reducer comprised by assembling | attaching a 1st speed change disk and a 2nd speed change disk with a phase difference of 180 degrees, and having comprised required components. (Example 7) which is the longitudinal cross-sectional view of the multistage reduction gear gear which comprised the 1st speed change disk and the 2nd speed change disk assembled | attached with the phase difference of 180 degrees, and illustrated the comparatively big reduction ratio. (A), (b) is a front view which shows an external tooth pinion and a pin pinion (Example 8). (Example 8) which is a longitudinal cross-sectional view which shows a multistage reduction gear. It is a longitudinal cross-sectional view which shows the conventional multistage speed reducer.

Explanation of symbols

1, 35, 61 Double-stage reduction gear 2 First eccentric gear 2a External tooth 2A Outer surface of first eccentric gear 3 First ring gear 3a Internal tooth 4 Crank input shaft 7 Input shaft 11 Second eccentric gear 11a External tooth 11A First 2 Outer surface of eccentric gear 12 Second ring gear 12a Internal tooth 12A Output shaft 13, Parallel biaxial constant velocity joint 13S Oldham joint (Parallel biaxial constant velocity joint)
13T Parallel biaxial constant velocity rotary joint 14, 15 Circular hole group 14a, 15a Circular hole 16 Rotation transmission body 20 Third ring gear 21 Third eccentric gear 36 Fixed disk 36A Input shaft 37 First transmission disk 38 First rolling ball 39 Second speed change disk 40, 41 Circular hole group 40a, 41a Circular hole 41A Output disk 42 Second rolling ball 43 First curved tooth groove 44 Second curved tooth groove 45 Third curved tooth groove 46, 68, 72 Ball type Parallel biaxial constant-velocity rotary joint 48 4th curve tooth groove 47, 75 Rolling ball body 49 Output shaft 59 3rd speed change disk 60 4th speed change disk 62 1st external tooth pinion 62a 1st pinion tooth 63 2nd external tooth Pinion 63a Second pinion tooth 64 First pin pinion 64a Cylindrical pin tooth (inner tooth of first pin pinion)
66 Second pin pinion 66a Cylindrical pin teeth (inner teeth of the second pin pinion)
70, 73 Circular holes P1, P4 Internal tooth pitch circle P2, P3 External tooth pitch circle Px1, Px3 First collective force point Px2, Px4 Second collective force point e1 First eccentric amount Ep1 First eccentric position e2 Second eccentric amount Ep2 Second 2 eccentric position

Claims (9)

A first eccentric gear which has a crank input shaft and meshes with the internal teeth of a fixed first ring gear, and performs a combined motion consisting of rotational displacement and turning displacement as the crank input shaft rotates;
The first eccentric gear is connected to the crank input shaft in an eccentric state, is provided so as to be freely rotatable with a number of teeth different from the inner teeth of the first ring gear, and meshes with the inner teeth of the second ring gear. Two eccentric gears,
A first transmission crankshaft provided to connect the first eccentric gear and the second eccentric gear;
The first eccentric gear and the second eccentric gear are connected to each other so that the combined motion of the first eccentric gear is transmitted to the second eccentric gear at a transmission ratio of 1: 1. Shaft constant velocity rotary joint,
The inner ring pitch circle of the first ring gear and the internal ring pitch circle of the second ring gear are set to the same dimension,
As the crank input shaft rotates, the rotational displacement of the combined motion of the first eccentric gear is transmitted to the second eccentric gear via the first transmission crankshaft and the parallel two-shaft constant velocity rotary joint. A multistage reduction gear device characterized in that a rotational displacement is output to a second ring gear. The parallel biaxial constant velocity rotary joint is
A series of circular hole groups respectively provided along the same pitch circle on the outer surface of the first eccentric gear and the outer surface of the second eccentric gear facing each other;
The first eccentric gear and the second eccentric gear are loosely fitted so as to be able to roll over the circular hole of the first eccentric gear and the circular hole of the second eccentric gear, with respect to the inner peripheral surface of the circular hole. A circular rotation transmission body with a gap according to the amount of eccentricity with
As the crank input shaft rotates, the rotation transmitting body rolls on the inner peripheral surfaces of the circular hole of the first eccentric gear and the circular hole of the second eccentric gear, thereby causing the first eccentric gear to rotate. 2. The multistage reduction gear according to claim 1, wherein the rotational displacement of the combined motion is transmitted to the second eccentric gear at a transmission ratio of 1: 1.   The first eccentric gear and the second eccentric gear are cycloid pinions, and the first ring gear and the second ring gear are pin pinions. The multistage reduction gear described. A fixed disk having a first curved tooth groove of a cycloid system formed in a circumferential direction along a first pitch circle on one side;
An input shaft is connected to face the fixed disk in an eccentric state with a first eccentric amount, and a surface portion corresponding to the first curved tooth groove follows a second pitch circle that is the same as the first pitch circle. A first speed change disk having a cycloid-type second curved tooth gap, the first curved tooth groove having a wave number difference of one or two with respect to the first curved tooth groove;
It is arranged over the first curved tooth gap and the second curved tooth groove, and is a combined motion comprising rotational displacement and turning displacement of the first transmission disk with respect to the fixed disk as the input shaft rotates. A plurality of first rolling balls that cause
A cycloid-type third curved tooth groove formed in the circumferential direction along a third pitch circle on the opposite side to the opposite side, facing the eccentric state with a second eccentric amount with respect to the first transmission disk. A second speed change disc having
A parallel twin shaft or the like provided between the first speed change disk and the second speed change disk and transmitting the rotational displacement of the combined movement of the first speed change disk to the second speed change disk with a transmission ratio of 1: 1. Fast rotating joints,
A fourth shift disk having an output shaft is provided on the second transmission disk so as to face the eccentric state with a third eccentric amount in the proximity of the eccentric state, and has the same dimension as the third pitch circle on the surface facing the third curved tooth groove. An output disk formed in a circumferential direction along a pitch circle and having a cycloid-based fourth curved tooth groove having a wave number difference of one or two with respect to the third curved tooth groove;
A plurality of second curved teeth are arranged between the third curved tooth gap and the fourth curved tooth groove, and absorbs a turning movement of the combined movement of the second speed change disk and transmits only the rotation displacement to the output disk. With two rolling balls,
A normal line of a tangent line that forms a pressure angle with each of the first rolling balls in contact with the first curved tooth groove of the fixed disk and the second curved tooth groove of the first speed change disk at a single point intersects. A tangent line that sets one collective force point and that forms a pressure angle by contacting each of the second rolling balls by meshing with the third curved tooth groove of the second speed change disk and the fourth curved tooth groove of the output disk. A second collective force point where the normals of the two intersect at one point is set, and the second eccentric force from the first eccentric position of the first eccentric amount to the first collective force point and the third eccentric position of the third eccentric amount A multistage speed reducer characterized by equalizing the distance to the collective power point. The parallel biaxial constant velocity rotary joint is
A series of circular hole groups formed on the first speed change disk and the second speed change disk facing each other along the same pitch circle and having a radial dimension corresponding to the second eccentricity amount,
It is arranged to roll over the circular hole of the first speed change disk and the circular hole of the second speed change disk, so that the rotational displacement of the combined movement of the first speed change disk is set at a transmission ratio of 1: 1. The multistage reduction gear according to claim 4, further comprising a plurality of rolling ball bodies that transmit to the second speed change disk. A combined motion comprising a first pinion tooth meshing with an inner tooth of a first pin pinion formed with a tooth surface profile based on a cycloid system curve on the outer periphery, and comprising a turning displacement and a rotational displacement while meshing with the first pin pinion A first external tooth pinion arranged in an eccentric state to perform
The first external tooth pinion has a second pinion tooth that is juxtaposed face-to-face and in an eccentric state and meshes with the internal tooth of the second pin pinion with a tooth surface profile based on a cycloid system curve, and meshes with the second pin pinion A second external tooth pinion that performs a combined motion consisting of turning displacement and rotation displacement,
Provided between the first external tooth pinion and the second external tooth pinion, and transmits the rotational displacement of the combined movement of the first external tooth pinion to the second external tooth pinion with a transmission ratio of 1: 1. A parallel biaxial constant velocity rotary joint;
An output disc juxtaposed with the second external tooth pinion in close proximity and in an eccentric state;
Parallel biaxial constant-speed rotation provided between the second external tooth pinion and the output disk and transmitting the rotational displacement of the combined movement of the second external tooth pinion to the output disk with a transmission ratio of 1: 1. With fittings,
While setting each of the first pinion teeth of the first external tooth pinion is in contact with the internal teeth of the first pin pinion by meshing, a tangential normal line forming a pressure angle intersects at one point, Each of the second pinion teeth of the second external pinion is in contact with the internal teeth of the second pin pinion by meshing to set a second collective force point where tangential normal lines forming a pressure angle intersect at one point;
The multi-stage characterized in that the distance from the eccentric position of the first external tooth pinion to the first collective force point is equal to the distance from the eccentric position of the second external tooth pinion to the second collective force point. Reducer. The parallel biaxial constant velocity rotary joint provided between the first external tooth pinion and the second external tooth pinion is:
A series of circular hole groups formed on the first external tooth pinion and the second external tooth pinion facing each other along the same pitch circle and having a radial dimension according to the eccentric state of the first external tooth pinion. When,
It is arranged to be able to roll over the circular hole of the first external tooth pinion and the circular hole of the second external tooth pinion, and the rotational displacement of the combined movement of the first external tooth pinion is 1: 1. A plurality of rolling ball bodies that transmit to the second external pinion at a transmission ratio of
The parallel biaxial constant velocity rotary joint provided between the second external tooth pinion and the output disk is:
A series of circular hole groups each formed in a radial dimension according to the eccentric state of the second external tooth pinion along the same pitch circle on the second external tooth pinion and the output disk facing each other;
A rolling ratio is provided between the circular hole of the first external tooth pinion and the circular hole of the output disk so that the rotational displacement of the combined movement of the first external tooth pinion is a 1: 1 transmission ratio. And a plurality of rolling ball bodies to be transmitted to the output disk.   The multistage reduction gear according to claim 6, wherein the first rolling ball and the second rolling ball are made of steel.   The multistage reduction gear according to claim 7, wherein the rolling ball body is made of steel.

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