CN219082192U - Planetary gear transmission speed reducer with small tooth difference and internal teeth - Google Patents

Abstract

The utility model relates to a small-tooth-difference internal tooth planetary gear transmission speed reducer, which consists of two stages of speed reducing mechanisms, wherein each stage adopts a parallelogram mechanism and a small-tooth-difference internal tooth planetary gear transmission mechanism combination. The first-stage speed reduction comprises a power input shaft, four groups of first eccentric assemblies axially overlapped, four annular internal gear translation plates, an external gear and a transmission shaft, wherein three or more internal gears are uniformly distributed on the annular internal gear translation plates along the circumference so as to split power and overcome dead points, and one power source drives the power input shaft to simultaneously output power from a plurality of transmission shafts to a second-stage speed reduction mechanism after the first-stage speed reduction; the second-stage speed reduction comprises two groups of second eccentric assemblies, two central internal gear translation plates and an external gear output shaft, wherein the second eccentric assemblies are assembled on each transmission shaft, and the external gear output shaft is coaxial with the input shaft. The virtual constraint is added to improve the transmission precision and rigidity, the dynamic loads of all support bearings are very small, the service life and the bearing capacity are prolonged, the starting inertia is small, and the manufacturing difficulty and the processing cost are reduced.

Description

Planetary gear transmission speed reducer with small tooth difference and internal teeth

Technical Field

The present utility model relates to a small tooth difference transmission device, and more particularly, to a small tooth difference internal tooth planetary gear transmission speed reducing device.

Background

The precise speed reducer applied by the existing articulated robot is mainly an RV speed reducer and a harmonic speed reducer.

The RV reducer consists of cylindrical gear planetary transmission and cycloidal pin gear planetary transmission with less tooth difference. Because the RV reducer is output through the planet carrier, the supporting bearings at the two ends of the crankshaft are required to bear load torque, the load is extremely large, the limiting point of the service life and the rotating speed of the reducer is formed, and the problem is more remarkable during high-speed running; secondly, in the manufacture of such precision reducers, in order to obtain a small return difference and to distribute the load uniformly, a very high manufacturing precision is required, the cycloidal pin gear transmission is sensitive to machining errors, resulting in very high product costs, and in addition, the reduction of the first stage planetary carrier gear transmission is relatively small and the starting inertia is large.

The harmonic speed reducer adopts a cam biphase shock wave planetary gear transmission mechanism with small tooth difference. The motion transmission is realized through the elastic deformation of the flexible bearing and the flexible gear, on one hand, the starting inertia is larger, and on the other hand, the return difference is larger when the load is transmitted due to insufficient rigidity, so that the positioning precision and the dynamic characteristic of the end effector of the robot are influenced; and under the action of alternating stress, the service life of the flexible bearing is greatly influenced, the harmonic transmission is obviously reduced along with the increase of the service time, and the improvement of the service life is restricted.

The existing internal tooth plate type planetary gear transmission device consists of a double crank mechanism and a planetary gear transmission mechanism with less tooth difference, which is shown in Chinese patent ZL 201420107993.4 in detail, and aims at the problem of periodic vibration of inertial force of a three-ring speed reducer. However, for the second-stage reduction gear with lower rotating speed, the virtual inertial force is small and can be ignored because of the lower rotating speed, while for the reduction gear applied to the articulated robot, the internal toothed plate is thinner, and the inertial force couple generated by the virtual inertial force is more negligible, so that the three or more internal toothed plates are adopted, not only are the axial structural size not necessarily increased, but also the weight and cost of the reduction gear are increased.

An existing ring type planetary transmission device is shown in embodiment 1 (see fig. 2) of the patent number 01247113.5 of Chinese patent ZL in detail, and is provided with a special mechanism for overcoming dead points, so that the structural size is enlarged and the manufacturing cost is increased; in the second embodiment (see fig. 3 and 4), three or more high-speed eccentric shafts drive two inner tooth plates to transmit motion and power, and obviously, inertia couples generated by the two inner tooth plates on the high-speed shaft cannot be completely balanced, and vibration is unavoidable; the power of the high-speed shaft with the structure can only be provided by a power source, and when the power source of the high-speed eccentric shaft is a plurality of power sources, the manufacturing cost is increased.

Disclosure of Invention

The utility model provides a planetary gear transmission speed reducer with small tooth difference and internal teeth, which avoids the defects of the existing speed reducer or speed reducer and further realizes the basic requirements of high precision, long service life, high bearing capacity, large transmission ratio and high rigidity of the precision speed reducer, and reduces the manufacturing cost of the precision speed reducer on the basis.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

the planetary gear transmission speed reducing device with the small tooth difference and internal teeth comprises a first-stage speed reducing mechanism and a second-stage speed reducing mechanism connected with the first-stage speed reducing mechanism, wherein the first-stage speed reducing mechanism comprises a power input shaft, four or three groups of first eccentric assemblies, four or three annular internal gear translation plates, an external gear and a transmission shaft, wherein the two ends of the power input shaft are supported by a first bearing, the four or three groups of first eccentric assemblies are arranged on the power input shaft in an axial overlapping manner, and the annular internal gear translation plates, the external gear and the transmission shaft are respectively arranged on the first eccentric assemblies; the first eccentric assembly comprises a first eccentric sleeve and second bearings respectively arranged on the outer surface of the first eccentric sleeve; the annular internal gear translation plate is provided with a second bearing mounting hole at the geometric center position and three or more internal gears uniformly distributed on the circumference taking the geometric center as the center of a circle; the external gear is fixedly connected with the transmission shaft and meshed with each corresponding internal gear; each internal gear is respectively meshed with the external gear to form a small-tooth-difference internal tooth planetary gear transmission; the tooth profiles of the inner gear and the outer gear are involute tooth profiles; three or more of the drive shafts simultaneously output motion and power to a second stage reduction mechanism.

In the technical scheme, the two sides of the power input shaft and the transmission shaft are respectively provided with a support bearing, the decelerating motion is formed by a parallelogram mechanism and a small-tooth-difference internal tooth planetary gear mechanism, the motion and power of the input power input shaft enable the annular internal gear translational plate (connecting rod) to generate circumferential translational motion through a first eccentric sleeve (crank) of the first eccentric assembly and translational circular waves excited by the second bearing, the annular internal gear translational plate is enabled to obtain a continuous translational circular wave, any point on the annular internal gear translational plate is enabled to do continuous circumferential translational motion with the eccentric distance of the first eccentric sleeve as a radius, so that the internal tooth gear performs planetary motion, and the decelerated motion and power are simultaneously output to a plurality of transmission shafts through the small-tooth-difference internal tooth planetary gear transmission; the moment of inertia of the four or three groups of first eccentric assemblies is small, so that the starting inertia is also small; the virtual constraint is increased by arranging three or more internal gears on the annular internal gear translation plate, so that motion and power are simultaneously transmitted to three or more transmission shafts by one power input shaft, namely, the virtual constraint is increased, the transmission precision is improved, the load of a transmission part is reduced by the power splitting action of a plurality of internal gears, the service life or the bearing capacity is improved, for an involute tooth profile, the internal gears are concave teeth and the external gears are convex teeth, the curvature centers of the internal teeth and the external teeth are in the same direction, the curvature radiuses are nearly equal, the contact area is large, the contact strength of the gear teeth is greatly improved, the bending strength of the gear teeth is also improved by adopting a short tooth system with less tooth difference, and the transmission is engaged by a plurality of pairs of gear teeth, so that the bearing capacity is further improved.

Preferably, the four first eccentric assemblies and the four annular internal gear translation plates are in the same phase, the two middle first eccentric assemblies are in the same phase, the two middle annular internal gear translation plates are in the same phase, the first eccentric assemblies at the two ends are in the same phase and 180 degrees out of phase with the two middle first eccentric assemblies, and the annular internal gear translation plates at the two ends are in the same phase and 180 degrees out of phase with the two middle annular internal gear translation plates. The thickness of each annular internal gear translation plate is equal, the material performance and the other structural dimensions are consistent, and the gear parameters and the directions of the internal gears are consistent; the geometric center of each annular internal gear translation plate is also the centroid of the annular internal gear translation plate. Because the structures of all the annular internal tooth translation plates are completely consistent, meshing forces of corresponding internal gears and corresponding external gears on the four annular internal tooth translation plates are 180-degree phase difference, the acting forces acting on each transmission shaft are balanced in opposite directions, so that the dynamic load of the support bearing of the transmission shaft is extremely small, and the service life of the support bearing is prolonged; the same action force on the power input shaft is balanced in opposite directions, so that the dynamic load of the support bearings on two sides of the power input shaft is extremely small, the longer service life is ensured, the four annular internal gear translation plates are arranged, the function of power splitting is also achieved, the dynamic load of the second bearing playing the role of shock wave is reduced, the service life of the second bearing is prolonged, the inertia couple generated by the eccentric part is completely balanced, the transmission is more stable, the effects of damping and noise reduction and part heating reduction are achieved, the transmission efficiency is improved, and the improvement of the rotation speed of the power input shaft is applied.

Preferably, the first eccentric assembly is three groups, the number of the annular internal gear translation plates is three, the thicknesses of the two annular internal gear translation plates at the two ends are equal, and the thickness of the middle annular internal gear translation plate is the sum of the thicknesses of the two annular internal gear translation plates at the two ends. The material performance and the other structural dimensions except the thickness dimension of each annular internal gear translation plate are consistent, and the other gear parameters and the directions of the internal gears except the tooth thickness parameter are consistent; the geometric center of each annular internal gear translation plate is also the centroid of the annular internal gear translation plate. The acting forces acting on each transmission shaft are balanced in the same direction, so that the dynamic load of the support bearing of the transmission shaft is extremely small, and the service life of the support bearing is prolonged; the acting forces acting on the power input shaft are balanced in opposite directions, so that the dynamic load acting on the support bearings at the two ends of the power input shaft is extremely small, the service life is prolonged, the three annular internal gear translation plates are arranged, the dynamic load of the second bearing acting on shock waves is reduced due to the power splitting effect, the service life of the second bearing is prolonged, the inertia couple generated by the eccentric part is completely balanced, the transmission is more stable, the effects of damping and noise reduction and part heating reduction are achieved, the transmission efficiency is improved, and the rotating speed of the power input shaft is increased.

Preferably, the internal gears are uniformly distributed on a circumference taking the geometric center of the annular internal gear translation plate as the center of a circle and having a radius R1; the axle center of the transmission shaft is uniformly distributed on a circumference taking the rotation center of the power input shaft as the circle center and the radius of the transmission shaft is R2, and R2=R1. The center distance of the external gear meshed with each internal gear is equal to the eccentric distance of the first eccentric sleeve, so that a parallelogram mechanism is formed, at least three internal gears are arranged, at least three parallelogram mechanisms with equal cranks and equal connecting rods exist, when one or two of the internal gears run to a dead point position, one power source can ensure that the rest of the parallelogram mechanisms overcome the dead point, so that the motion certainty is ensured.

Preferably, the external gear is fixedly connected with the transmission shaft, wherein the external gear is provided with an internal spline, and the transmission shaft is an external spline transmission shaft, so that the centering and transmission precision are ensured; the two ends of the transmission shaft are supported by the third bearing, the transmission shaft is supported by the fourth bearing between the first-stage reduction mechanism and the second-stage reduction mechanism, and the third bearing and the fourth bearing are arranged on the shell fixedly-connected piece, so that the rigidity of the reduction gear is improved.

Preferably, the second-stage reduction mechanism comprises two groups of second eccentric assemblies, two central internal gear translation plates and external gear output shafts, wherein the second eccentric assemblies are arranged on each transmission shaft in an axially overlapped mode, the two central internal gear translation plates are respectively arranged on the outer surfaces of the second eccentric assemblies, and the two external gear output shafts are supported by fifth bearings at the two ends of each external gear translation plate; the second eccentric assembly comprises a second eccentric sleeve and a sixth bearing which is respectively arranged on the outer surface of the second eccentric sleeve, and as virtual constraint is added, the dynamic load born on the sixth bearing is reduced, and the service life of the sixth bearing is prolonged; the second eccentric sleeve is provided with an internal spline, and is fixedly connected with the transmission shaft through the internal spline, so that the neutrality and the transmission precision are ensured; the center internal gear translation plate is provided with sixth bearing mounting holes and center internal gears, the number of which corresponds to that of the transmission shafts, so that power confluence is realized; the central internal gear and an external gear on the external gear output shaft form a small-tooth-difference internal gear planetary gear transmission; the tooth profile of the central internal gear and the tooth profile of the external gear on the external gear output shaft are involute tooth profiles, and the central internal gear is arranged at the geometric center position with larger structural dimension allowance because the central internal gear has the characteristics of large contact strength, high bending strength and multi-tooth meshing, so that the bearing capacity is improved after the power is converged, and the transmission ratio of the speed reduction device is further increased after the second-stage speed reduction.

Preferably, the sixth bearing mounting holes are uniformly arranged on a circumference taking the geometric center of the central internal gear translation plate as a circle center and taking R3 as a radius, and r3=r1=r2; the center distance between the center internal gear and the output shaft of the external gear meshed with the center internal gear is equal to the eccentric distance of the second eccentric sleeve; the center internal gear is positioned at the geometric center of the center internal gear translation plate, and the external gear output shaft is coaxial with the power input shaft. The motion and power are input by three or more transmission shafts at the same time, the second eccentric sleeve (crank) and the sixth bearing shock wave enable the center internal gear translation plate (connecting rod) to generate circumferential translation, the center internal gear translation plate is enabled to obtain continuous translation circular wave, any point on the center internal gear translation plate is enabled to do continuous circumferential translation with the eccentricity of the second eccentric sleeve as radius, therefore the internal gear is enabled to do planetary motion, then the motion and power are output by the external gear output shaft after being decelerated through the small tooth difference internal gear planetary gear transmission mechanism, virtual constraint is further increased relative to the first-stage reduction mechanism, and transmission precision and rigidity are further improved.

Preferably, the phase difference of the two central internal gear translation plates is 180 degrees, all structural dimensions and material properties of each central internal gear translation plate are consistent, and gear parameters and orientations of the central internal gears are consistent; the geometric center of each central internal gear translation plate is also the centroid thereof. The meshing forces of the central internal gear on the two central internal gear translation plates and the external gear on the external gear output shafts are 180-degree phase difference, the acting forces acting on each external gear output shaft are balanced in opposite directions, so that the dynamic load born by a fifth bearing with two ends supporting the external gear output shafts is extremely small, and the service life is prolonged.

Compared with the prior art, the utility model has the beneficial effects that: the dynamic load born by all the support bearings is small, so that the limitation of the service life of the speed reducer due to the service life of the bearings is avoided; the transmission precision and rigidity are greatly improved by adding virtual constraint, so that return difference is smaller when load is transmitted, and the defect that the positioning precision and dynamic characteristics of the end effector of the robot are influenced is overcome; the starting inertia is reduced, the manufacturing difficulty of the precision speed reducer is reduced, and the processing cost is reduced; the bearing capacity is improved.

Drawings

FIG. 1 is a schematic diagram of a small tooth difference internal tooth planetary gear transmission reduction gear according to embodiment 1 of the present utility model;

FIG. 2 is a cross-sectional view of A-A of FIG. 1;

FIG. 3 is a schematic view of the structure of the annular internal tooth translation plate of the present utility model;

fig. 4 is a schematic structural view of a small-tooth-difference internal tooth planetary gear transmission reduction gear according to embodiment 3 of the present utility model;

FIG. 5 is a cross-sectional view of B-B of FIG. 1;

fig. 6 is a schematic structural view of the central internal gear translation plate of the present utility model.

Detailed Description

The drawings are for illustrative purposes only and are not to be construed as limiting the present patent; for the purpose of better illustrating the embodiments, certain elements of the drawings may be omitted, enlarged or reduced and do not represent the size of the actual product; it will be appreciated by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted. The positional relationship depicted in the drawings is for illustrative purposes only and is not to be construed as limiting the present patent.

The same or similar reference numbers in the drawings of embodiments of the utility model correspond to the same or similar components; in the description of the present utility model, it should be understood that, if there are orientations or positional relationships indicated by terms "upper", "lower", "left", "right", "long", "short", etc., based on the orientations or positional relationships shown in the drawings, this is merely for convenience in describing the present utility model and simplifying the description, and is not an indication or suggestion that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so that the terms describing the positional relationships in the drawings are merely for exemplary illustration and are not to be construed as limitations of the present patent, and that it is possible for those of ordinary skill in the art to understand the specific meaning of the terms described above according to specific circumstances.

The technical scheme of the utility model is further specifically described by the following specific embodiments with reference to the accompanying drawings:

example 1

As shown in fig. 1-3, an embodiment 1 of a small-tooth-difference internal tooth planetary gear transmission speed reducing device is shown, a first-stage speed reducing mechanism comprises a power input shaft 1, four or three groups of first eccentric assemblies 2, four or three annular internal gear translation plates 3, external gears 4 and a transmission shaft 5, wherein the two ends of the power input shaft 1 are supported by a first bearing 101, the four groups or three groups of first eccentric assemblies 2 are installed on the power input shaft 1 and are arranged in an overlapping manner along the axial direction, and the annular internal gear translation plates 3, the external gears 4 and the transmission shaft 5 are respectively installed on the first eccentric assemblies 2; the first eccentric assembly 2 comprises a first eccentric sleeve 201 and second bearings 202 respectively arranged on the outer surface of the first eccentric sleeve 201; the annular internal gear translation plate 3 is provided with a second bearing mounting hole 301 at the geometric center position thereof, and three or more internal gears 302 are uniformly distributed on the circumference taking the geometric center as the center of a circle; the external gear 4 is fixedly connected with the transmission shaft 5 and meshed with each corresponding internal gear 302; the inner gears 302 respectively form a planetary gear transmission with small teeth difference and inner teeth with the meshed outer gears 4; the tooth profiles of the inner gear 302 and the outer gear 4 are involute tooth profiles; three or more drive shafts 5 simultaneously output motion and power to the second stage reduction mechanism.

In this embodiment, the first eccentric assemblies 2 are four groups and the annular internal gear translational plates 3 are four, the first eccentric assemblies 2 of the middle two groups are in phase, the two annular internal gear translational plates 3 of the middle two groups are in phase, the first eccentric assemblies 2 of the two ends are in phase and 180 degrees out of phase with the first eccentric assemblies 2 of the middle two groups, and the annular internal gear translational plates 3 of the two ends are in phase and 180 degrees out of phase with the two annular internal gear translational plates 3 of the middle two groups. The thickness of each annular internal gear translation plate 3 is equal, the material performance and the other structural dimensions are consistent, and the gear parameters and the directions of the internal gears 302 are consistent; the geometric center of each annular ring gear translation plate 3 is also the centroid thereof. Because the structures of all the annular internal tooth translation plates are completely consistent, the meshing forces of the corresponding internal gears 302 and the corresponding external gears 4 on the four annular internal tooth translation plates are 180-degree phase difference, the acting forces acting on each transmission shaft 5 are balanced in opposite directions, so that the dynamic load of the support bearing of the transmission shaft 5 is extremely small, and the service life is prolonged; the forces acting on the power input shaft 1 are balanced in opposite directions, so that the dynamic loads acting on the support bearings on two sides of the power input shaft 1 are extremely small, the longer service life is ensured, the four annular internal gear translation plates 3 are arranged, the dynamic loads of the second bearing 202 acting on shock waves are reduced due to the function of power splitting, the service life of the second bearing 202 is prolonged, the inertia couple generated by the eccentric part is completely balanced, the transmission is more stable, the effects of damping, noise reduction and part heating reduction are achieved, the transmission efficiency is improved, and the improvement of the rotating speed of the power input shaft 1 is applied.

Specifically, the internal gears 302 are uniformly distributed on a circumference with the geometric center of the annular internal gear translational plate 3 as the center and the radius R1; the axle center of the transmission shaft 5 is uniformly distributed on a circumference which takes the rotation center of the power input shaft 1 as the circle center and has a radius of R2, and R2=R1; the center distance of the external gear 4 with which each internal gear 302 is meshed is equal to the eccentricity of the first eccentric sleeve 201, thus forming a parallelogram mechanism, while each internal gear 302 is provided with at least three parallelogram mechanisms with at least three equal cranks and equal connecting rods, when one or two of the internal gears run to the dead point position, one power source can ensure that the rest of the parallelogram mechanisms overcome the dead point, thereby ensuring the certainty of movement.

Further, the external gear 4 is fixedly connected with the transmission shaft 5, wherein the external gear 4 is provided with an internal spline, and the transmission shaft 5 is an external spline transmission shaft, so that the centering and transmission precision are ensured; the two ends of the transmission shaft 5 are supported by the third bearing 501, the transmission shaft 5 is provided with a fourth bearing 502 between the first-stage reduction mechanism and the second-stage reduction mechanism, the third bearing 501 and the fourth bearing 502 are arranged on the shell of the shell fastening piece, and the rigidity of the reduction gear is improved.

The working principle of the embodiment is as follows: the two ends of the power input shaft 1 and the transmission shaft 5 are respectively provided with a support bearing 101 and a third bearing 501, the decelerating motion is formed by a parallelogram mechanism and a small-tooth-difference internal tooth planetary gear transmission mechanism, the motion and power of the input power input shaft 1 make the annular internal gear translational plate 3 (connecting rod) generate circumferential translational motion through translational circular waves excited by a first eccentric sleeve 201 (crank) and a second bearing 202 of a first eccentric assembly 2, the annular internal gear translational plate 3 obtains a continuous translational circular wave, any point of the annular internal gear translational circular wave takes the eccentric distance of the first eccentric sleeve 201 as the continuous circumferential translational motion of the radius, so that the internal gear 302 performs planetary motion, and each transmission shaft 5 simultaneously obtains a decelerated continuous rotation output through the small-tooth-difference internal tooth planetary gear transmission; the moment of inertia of the four or three groups of first eccentric assemblies 2 is small, so that the starting inertia is also small; the virtual constraint is increased by arranging three or more internal gears 302 on the annular internal gear translation plate 3, so that motion and power are transmitted to three or more transmission shafts 5 by one power input shaft 1, namely, the virtual constraint is increased, the transmission precision is improved, the load of a transmission part is reduced by the power splitting action of a plurality of internal gears 302, the service life or the carrying capacity is improved, for an involute tooth profile, the internal gears 302 are concave teeth, the external gears 4 are convex teeth, the curvature centers of the internal teeth and the external teeth are in the same direction, the curvature radiuses are approximately equal, the contact area is large, the contact strength of gear teeth is greatly improved, the short teeth adopted by small tooth difference are made, the bending strength of the gear teeth is also improved, the transmission is realized by the engagement of a plurality of pairs of gear teeth, the carrying capacity is further improved, in addition, the involute gear transmission is insensitive to processing, the processing precision is easy to ensure, and the processing cost is also reduced.

The beneficial effects of this embodiment are: the dynamic load born by all the support bearings is small, so that the limitation of the service life of the speed reducer due to the service life of the bearings is avoided; the transmission precision and rigidity are greatly improved by adding virtual constraint, so that return difference is smaller when load is transmitted, and the defect that the positioning precision and dynamic characteristics of the end effector of the robot are influenced is overcome; the starting inertia is reduced, the manufacturing difficulty of the precision speed reducer is reduced, and the processing cost is reduced; the bearing capacity is improved.

Example 2

An embodiment 2 of a planetary gear transmission speed reducing device with small tooth difference and internal teeth is different from embodiment 1 in that the first eccentric assembly 2 is three groups, the number of the annular internal gear translation plates 3 is three, the thicknesses of two annular internal gear translation plates 3 at two ends are equal, and the thickness of the middle annular internal gear translation plate 3 is the sum of the thicknesses of the two annular internal gear translation plates 3 at two ends. The rest structural dimensions of each annular internal gear translation plate 3 except the thickness dimension are consistent, and the rest gear parameters and the positions of each internal gear 302 except the tooth thickness parameters are consistent; the geometric center of each annular ring gear translation plate 3 is also the centroid thereof. The acting forces acting on each transmission shaft 5 are balanced in the same direction, so that the dynamic load of the support bearing of the transmission shaft 5 is extremely small, and the service life is prolonged; the forces acting on the power input shaft 1 are balanced in opposite directions, so that the dynamic load acting on the support bearings on two sides of the power input shaft 1 is extremely small, the longer service life is ensured, the three annular internal gear translation plates 3 are arranged, the dynamic load of the bearings is reduced by the power splitting effect, the service life of the second bearing 202 is prolonged, the inertia couple generated by the eccentric part is completely balanced, the transmission is more stable, the effects of damping, noise reduction and part heating reduction are achieved, the transmission efficiency is improved, and the improvement of the rotating speed of the power input shaft 1 is applied.

The remaining features and operation principle of the present embodiment are the same as those of embodiment 1.

Example 3

As shown in fig. 4, an embodiment 3 of a small-tooth-difference internal tooth planetary gear transmission speed reducing device is further defined as a second-stage speed reducing mechanism based on embodiment 1 or embodiment 2.

The second-stage reduction mechanism comprises a planetary gear 9 arranged on the transmission shaft 5, a fixed internal gear 10 meshed with the external gear of the planetary gear 9, transmission shaft support bearings 11 positioned at two ends of the transmission shaft 5, an input-end planetary plate 12 and an output-end planetary plate 13; the two ends of the transmission shaft 5 are respectively arranged on the input end planetary plate 12 and the output end planetary plate 13 through transmission shaft supporting bearings 11. The drive shaft support bearing 11 of the present embodiment corresponds to a crank shaft support bearing in the related art. Specifically, the planetary gear 9 is provided with an internal spline, and is fixedly connected with the transmission shaft 5 through the spline.

The second reduction is fixed by an internal gear, and an external gear is composed of a planetary gear and a planetary carrier. The motion and power input from each transmission shaft 5 of the first-stage reduction mechanism enable the planetary gears 9 fixedly connected to the transmission shafts 5 through the splines to generate rotary motion, the planetary gears 9 are meshed with the fixed internal gear 10 to reduce speed, the support bearings 11 of the transmission shafts 5 drive the planetary carriers formed by the input end planetary plates 9 and the output end planetary plates 13 to rotate, and finally the output end planetary plates 13 output the motion and power.

Because the speed reduction of the first-stage few-tooth-difference internal tooth planetary gear transmission is performed, and the few-tooth-difference internal tooth planetary gear transmission has the characteristic of large transmission ratio, the rotating speed of the transmission shaft 5 is lower, and although the supporting bearing 11 of the transmission shaft 5 also needs to bear load torque, compared with the RV speed reducer, the RV speed reducer has higher rotating speed of a crankshaft because the speed reduction ratio of the first-stage planetary gear is small, so the service life of the supporting bearing of the transmission shaft 5 is longer than that of the supporting bearing of the RV crankshaft, and the supporting bearing of the transmission shaft 5 with smaller size can be selected on the premise of meeting the strength and the rigidity of the transmission shaft 5.

The first-stage reduction mechanism of the present embodiment corresponds to embodiment 1 or embodiment 2.

Example 4

As shown in fig. 1-3, 5 and 6, an embodiment 3 of a planetary gear transmission with small teeth difference and internal teeth is shown, and the secondary reduction mechanism is further defined on the basis of embodiment 1 or embodiment 2.

Specifically, the second-stage reduction mechanism comprises two groups of second eccentric assemblies 6 which are arranged on each transmission shaft 5 in an overlapping manner along the axial direction, two center internal gear translation plates 7 which are respectively arranged on the outer surfaces of the second eccentric assemblies 6, and an external gear output shaft 8 with two ends supported by a fifth bearing 401; the second eccentric assembly 6 comprises a second eccentric sleeve 601 and a sixth bearing 602 (specifically, a needle bearing) respectively arranged on the outer surface of the second eccentric sleeve 601, and due to the addition of virtual constraint, the dynamic load born on the sixth bearing 602 is reduced, and the service life of the sixth bearing 602 is prolonged; the second eccentric sleeve 601 is provided with an internal spline, and is fixedly connected with the transmission shaft 5 through the internal spline, so that the neutrality and the transmission precision are ensured; the center internal gear translation plate 7 is provided with sixth bearing mounting holes 701 and center internal gears 702 which correspond to the transmission shafts 5 in number, so that power confluence is realized; the external gear output shaft 8 and the central internal gear 702 form an internal gear 302 with less tooth difference planetary gear transmission; the tooth profiles of the central internal gear 702 and the external gear output shaft 8 are involute tooth profiles, and the central internal gear 702 is arranged at a geometric center position with larger structural dimension allowance, so that the bearing capacity after power confluence is improved, and the transmission ratio of the speed reducer is further increased after the second-stage speed reduction.

In the present embodiment, the sixth bearing mounting holes 701 are uniformly arranged on a circumference with R3 as a radius around the geometric center of the central internal gear translational plate 7, and r3=r1=r2; the center distance between the center internal gear 702 and the external gear output shaft 8 meshed with the center internal gear is equal to the eccentricity of the second eccentric sleeve 601; the central internal gear 702 is positioned at the geometric center of the central internal gear translation plate 7, and the external gear output shaft 8 is coaxial with the power input shaft 1. The motion and power are simultaneously input by three or more transmission shafts 5, the second eccentric sleeve 601 (crank) and the sixth bearing 602 shock waves enable the center internal gear 702 translational plate (connecting rod) to generate circumferential translational motion, the center internal gear translational plate 7 is enabled to obtain continuous translational circular waves, any point on the circular waves is enabled to do continuous circumferential translational motion with the eccentric distance of the second eccentric sleeve 601 as a radius, the center internal gear 702 is enabled to do planetary motion, and then the motion and power are output by an external gear output shaft after being decelerated by the small-tooth-difference internal gear planetary gear transmission mechanism, compared with the first-stage reduction mechanism, virtual constraint is further increased, and transmission precision and rigidity are further improved. The phase difference of the two central internal gear translation plates 7 is 180 degrees, all the structural dimensions and the material properties of each central internal gear translation plate 7 are consistent, and the gear parameters and the directions of the central internal gears 702 are consistent; the geometric center of each central internal gear translational plate 7 is also its centroid. The meshing forces of the central internal gear 702 on the two central internal gear translation plates and the external gear on the external gear output shaft 8 are 180 degrees out of phase, the forces acting on each external gear output shaft 8 are balanced in opposite directions, so that the dynamic load born by the bearing for supporting the external gear output shaft 8 is extremely small, and the service life is prolonged.

The first-stage reduction mechanism of the present embodiment corresponds to embodiment 1 and embodiment 2.

It is to be understood that the above examples of the present utility model are provided by way of illustration only and are not limiting of the embodiments of the present utility model. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the utility model are desired to be protected by the following claims.

Claims (10)

1. The planetary gear transmission speed reducing device with the small tooth difference and internal teeth is characterized by comprising a first-stage speed reducing mechanism and a second-stage speed reducing mechanism connected with the first-stage speed reducing mechanism, wherein the first-stage speed reducing mechanism comprises a power input shaft (1) with two ends supported by a first bearing (101), four or three groups of first eccentric assemblies (2) which are arranged on the power input shaft (1) in an axial overlapping manner, and four or three annular internal gear translation plates (3), external gears (4) and transmission shafts (5) which are respectively arranged on the first eccentric assemblies (2); the first eccentric assembly (2) comprises a first eccentric sleeve (201) and second bearings (202) respectively arranged on the outer surfaces of the first eccentric sleeve (201); the annular internal gear translation plate (3) is provided with a second bearing mounting hole (301) at the geometric center position thereof, and three or more internal gears (302) are uniformly distributed on the circumference taking the geometric center as the center of a circle; the external gear (4) is fixedly connected with the transmission shaft (5) and meshed with each corresponding internal gear (302); each internal gear (302) forms a small tooth difference internal tooth planetary gear transmission with the external gear (4) meshed with the internal gear; the tooth profiles of the inner gear (302) and the outer gear (4) are involute tooth profiles; three or more of the drive shafts (5) simultaneously output motion and power to a second stage reduction mechanism.

2. The planetary gear transmission speed reducer with small tooth difference and internal teeth according to claim 1, wherein the first eccentric assemblies (2) are four groups and the annular internal gear translation plates (3) are four, the middle two groups of first eccentric assemblies (2) are in phase, the middle two annular internal gear translation plates (3) are in phase, the first eccentric assemblies (2) at two ends are in phase and 180 degrees out of phase with the middle two groups of first eccentric assemblies (2), and the annular internal gear translation plates (3) at two ends are in phase and 180 degrees out of phase with the middle two annular internal gear translation plates (3).

3. A small tooth difference internal tooth planetary gear transmission reducing device according to claim 2, wherein each annular internal tooth gear translation plate (3) has equal thickness, consistent material property and rest structural dimension, and consistent gear parameters and orientation of each internal tooth gear (302); the geometric center of each annular internal gear translation plate (3) is also the centroid of the annular internal gear translation plate.

4. The planetary gear transmission speed reducer with small tooth difference and internal teeth according to claim 1, wherein the first eccentric assembly (2) is three groups, the number of the annular internal gear translation plates (3) is three, the thicknesses of the two annular internal gear translation plates (3) at two ends are equal, and the thickness of the annular internal gear translation plate (3) in the middle is the sum of the thicknesses of the two annular internal gear translation plates (3) at two ends.

5. A small tooth difference internal tooth planetary gear transmission reducing device according to claim 4, wherein the material property and the rest of the structure size except the thickness size of each annular internal tooth gear translation plate (3) are consistent; the rest gear parameters except the tooth thickness parameters of the internal gears (302) are consistent in azimuth; the geometric center of each annular internal gear translation plate (3) is also the centroid of the annular internal gear translation plate.

6. A small tooth difference internal tooth planetary gear transmission reducing device as defined in any one of claims 1-5, wherein each internal gear (302) is uniformly distributed on a circumference with the geometric center of said annular internal gear translational plate (3) as the center and the radius R1; the axle center of the transmission shaft (5) is uniformly distributed on a circumference taking the rotation center of the power input shaft (1) as the circle center and the radius of the transmission shaft is R2, and R2=R1; the center distance of the external gear (4) with which each internal gear (302) is meshed is equal to the eccentricity of the first eccentric sleeve (201).

7. The planetary gear transmission speed reducer with small tooth difference and internal teeth according to claim 1, wherein the external gear (4) is fixedly connected with the transmission shaft (5), wherein an internal spline is arranged on the external gear (4), and the transmission shaft (5) is an external spline transmission shaft; the two ends of the transmission shaft (5) are supported by a third bearing (501), and the transmission shaft (5) is provided with a fourth bearing (502) between the first-stage reduction mechanism and the second-stage reduction mechanism for supporting.

8. A small tooth difference internal tooth planetary gear transmission speed reducer as claimed in claim 1, characterized in that said second stage speed reducer comprises two second eccentric assemblies (6) mounted on each of said transmission shafts (5) and arranged in axial overlapping, two central internal tooth translational plates (7) respectively mounted on the outer surfaces of said second eccentric assemblies (6), and external tooth output shafts (8) with both ends supported by fifth bearings (401); the second eccentric assembly (6) comprises a second eccentric sleeve (601) and sixth bearings (602) respectively arranged on the outer surfaces of the second eccentric sleeve (601); the second eccentric sleeve (601) is provided with an internal spline, and is fixedly connected with the transmission shaft (5) through the internal spline; the center internal gear translation plate (7) is provided with sixth bearing mounting holes (701) and center internal gears (702) which are corresponding to the transmission shafts (5), and the sixth bearings (602) are mounted in the sixth bearing mounting holes (701); the central internal gear (702) and an external gear on the external gear output shaft (8) form a small-tooth-difference internal tooth planetary gear transmission; the tooth profile of the external gear on the central internal gear (702) and the external gear output shaft (8) is an involute tooth profile.

9. A small tooth difference internal tooth planetary gear transmission reducing device as defined in claim 8, wherein the sixth bearing mounting holes (701) are uniformly arranged on a circumference with the geometric center of the central internal gear translational plate (7) as the center and R3 as the radius, and r3=r1=r2; the center distance between the center internal gear (702) and the outer gear output shaft (8) meshed with the center internal gear is equal to the eccentricity of the second eccentric sleeve (601); the central internal gear (702) is positioned at the geometric center of the central internal gear translation plate (7); the external gear output shaft (8) is coaxial with the power input shaft (1).

10. The small-tooth-difference internal tooth planetary gear transmission speed reducer according to claim 8, wherein the phase difference of two central internal gear translation plates (7) is 180 degrees, all structural dimensions and material properties of each central internal gear translation plate (7) are consistent, and the gear parameters and the directions of each central internal gear (702) are consistent; the geometric center of each central internal gear translation plate (7) is also the centroid thereof.

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