CN114962559A

CN114962559A - Thin cycloidal pin gear speed reducer

Info

Publication number: CN114962559A
Application number: CN202210597467.3A
Authority: CN
Inventors: 王伟; 邹金洲
Original assignee: Wuhan University WHU
Current assignee: Wuhan University WHU
Priority date: 2022-05-30
Filing date: 2022-05-30
Publication date: 2022-08-30

Abstract

The invention discloses a thin cycloidal pin gear speed reducer which comprises an input eccentric generator, a disc type cycloidal pin gear speed reducing structure, a mounting structure and a rear driving motor. The input eccentric generator comprises an installation flange plate, an eccentric generation bearing installation pin, an eccentric generation bearing and a first gasket; the disk type cycloidal pin wheel speed reducing structure comprises a cycloidal wheel disc, a peripheral roller, a roller mounting pin, upper and lower side mounting pin fixing flange rings, an output bearing retaining ring and a copper column; the mounting structure comprises an output flange ring, a mounting flange ring and an output bearing. The eccentric inertia of the parts is extremely small, so that the high-speed working condition is adapted; the cycloidal pin wheel structure has high bearing capacity and is matched with high-speed input, so that high power density is realized; the cycloidal pin gear speed reducer has obvious power density advantage while ensuring higher precision, and eliminates the high-speed vibration problem of the traditional cycloidal pin gear speed reducer to a certain extent.

Description

Thin cycloidal pin gear speed reducer

Technical Field

The invention relates to the technical field of robots, in particular to a thin cycloidal pin gear speed reducer suitable for a robot joint.

Background

For a robot joint, a large moment is often required, but the requirement on the rotating speed is not high. This has led to the necessity of using a reduction gear to increase the joint torque. At present, speed reducers mainly adopted in the robot industry comprise a harmonic speed reducer and an RV speed reducer, but flexible gears of the harmonic speed reducer have the problems of poor rigidity and weak overload resistance, the RV speed reducer adopts two modes of gear reduction and cycloidal pin gear reduction to be cascaded, the mass is usually large, and the RV speed reducer is not suitable for a mobile robot. In the prior art solutions in the field of mobile robots, a deceleration solution with high bearing capacity and high energy density is lacking.

At present, chinese patent publication No. CN113915295A discloses a differential cycloidal pin gear speed reducer, which mainly comprises a crankshaft, a housing, two sets of pin gear needles, two cycloidal gears, and a driving motor. The main characteristics are as follows: the speed reduction is realized through the differential speed of two sets of cycloidal pin gear speed reducers with different tooth numbers, wherein a first-stage pin gear is fixed, two cycloidal gears are fixedly connected and share the same crankshaft, and a second-stage pin gear is output, so that a larger speed reduction ratio is mainly realized, and the output rigidity is ensured. However, the asymmetric structure is adopted on the high-speed side, and the unbalanced mass of the asymmetric structure is large, which causes that the reducer has large vibration when inputting at high speed, so that the reducer is not suitable for the high-speed robot joint.

At present, chinese patent publication No. CN113565932A discloses a cycloidal planetary gear speed reducing mechanism, which adopts symmetrical cycloidal ball speed reduction and first-stage planetary gear speed reduction of a first-stage harmonic-like speed reducer, and realizes the effect similar to an RV speed reducer through cascading, and simultaneously ensures the running stability of the speed reducer. However, in the cycloidal speed reduction link, large sliding friction exists between the steel balls and the matching parts of the steel balls, so that the rated input speed of the speed reducer is greatly limited, and meanwhile, the steel balls are in point contact matching, so that the input torque of the speed reducer is also greatly limited.

Disclosure of Invention

The invention provides a thin cycloidal pin gear speed reducer, which aims to overcome the defects of a mobile robot joint speed reducer in the prior art, mainly solves the problems of the joint speed reducer in the aspects of load capacity and the like, and improves the energy density of the joint speed reducer.

The technical problem of the invention is mainly solved by the following technical scheme:

a thin cycloidal pin gear speed reducer is characterized in that: the device comprises an input eccentric generator, a disc type cycloid pin wheel speed reducing structure, a mounting structure and a rear driving motor; wherein the content of the first and second substances,

the input eccentric generator is provided with two groups of eccentric generating bearings which are respectively in a same circle, the circle center of each group of the eccentric generating bearings in the same circle is respectively offset by an eccentric distance relative to the rotating center,

the disc type cycloidal pin wheel speed reducing structure comprises a cycloidal wheel disc, a peripheral roller, a roller mounting pin, a mounting pin fixing flange ring, an output bearing and an output bearing retaining ring; the cycloid discs are symmetrically arranged to counteract the centrifugal force of eccentric motion of the cycloid discs and output torque outwards;

the two groups of eccentric generating bearings respectively act on the two cycloid discs, and an input eccentric generator rotates around the geometric center of the input eccentric generator to generate an eccentric harmonic band movable disc type cycloid pinwheel speed reducing structure to realize a speed reducing function; the number of peripheral rollers of the disc type cycloidal pin wheel speed reducing structure is 1 more than that of the cycloidal wheel disc;

the mounting structure realizes the use and mounting of the speed reducer and the torque output;

the rear driving motor is installed through a motor installation flange hole on the input eccentric generator, and is fixed through a plurality of penetrating structure assembly screws installed on the outer ring flange and the motor installation plate.

Further, the input eccentricity generator comprises a mounting flange plate, an eccentricity generation bearing mounting pin, an eccentricity generation bearing and a plurality of first gaskets; two ends of an eccentric generating bearing mounting pin are respectively fixed on the mounting flange plates at the upper side and the lower side, and an eccentric generating bearing and the first gasket are both mounted on the eccentric generating bearing mounting pin; the eccentric generating bearings are divided into two groups, are oppositely and symmetrically arranged from top to bottom and are respectively in a same circle, and the installation height of the eccentric generating bearings is adjusted through a first gasket, so that the flange edges of the two groups of eccentric generating bearings are positioned at the same height.

Furthermore, the disk-type cycloidal pin wheel speed reduction structure comprises two cycloidal wheel discs, a plurality of roller mounting pins, peripheral rollers, an upper mounting pin fixing flange ring and a lower mounting pin fixing flange ring, wherein the peripheral rollers correspond to the roller mounting pins in number; the cycloid wheel disc is arranged between the upper side mounting pin fixing flange ring and the lower side mounting pin fixing flange ring; through holes are uniformly distributed on the cycloid discs, output bearing bearings are arranged in the through holes, and the output bearing bearings are simultaneously tangent to the two cycloid discs and used for outputting torque outwards.

Furthermore, the flange edge of the eccentric bearing of the cycloid wheel disc is used for separating the two cycloid wheel discs, and the inner hole of the cycloid wheel disc is tangent to the flange edge of the eccentric bearing of the cycloid wheel disc.

Furthermore, the mounting structure comprises an output flange ring, a mounting flange ring and an output bearing;

an output flange ring is arranged on the inner side of the output bearing, an output flange threaded hole is formed in the output flange ring, torque is output outwards, an installation flange ring is arranged on the outer side of the output bearing, and an installation flange threaded hole and an assembly flange threaded hole are formed in the installation flange ring; the mounting flange threaded hole is used for mounting a speed reducer, and the mounting flange threaded hole is used for being fixedly connected with the disc type cycloid pinwheel speed reducing structure.

The output flange ring is provided with two groups of threaded holes with a plurality of numbers, one group of output flange threaded holes is used for installing an output structural member, the other group of output flange threaded holes is an installation hole of the torque output screw, and the other end of the torque output screw penetrates through the output bearing; the structural assembling screws sequentially penetrate through the mounting flange ring, the upper side mounting pin fixing flange ring and the lower side mounting pin fixing flange ring.

Therefore, compared with the prior art, the invention has the following advantages:

1. high transmission efficiency and long service life. In the whole structure, only the peripheral ceramic roller and the ceramic roller mounting pin are in sliding friction, but the special ceramic has excellent self-lubricating and wear-resisting characteristics. In addition, all torque transmission fit is fixed fit or rolling fit, and rolling friction is far smaller than sliding friction, so that the working efficiency of the speed reducer is greatly improved. Meanwhile, rolling abrasion is small, and the service life of the speed reducer is prolonged.

2. High input speed and high precision. The mechanism adopts a symmetrical input eccentric generator, and has smaller vibration under high rotating speed compared with the traditional crankshaft, and in addition, the cycloid wheel disc adopts an ultrathin design, so that the centrifugal force is counteracted to the greatest extent by the two symmetrically moving wheel discs, and the vibration is reduced. Therefore, the high-speed input of more than ten thousand revolutions per minute can be realized, and the mobility of the robot joint is improved. Compared with the traditional multistage planetary reducer, the assembly size chain is shorter, only three relative motion connections exist, and higher operation precision can be realized under the same machining precision.

3. Small volume and high power density. The speed reducer adopts a flat design, and the rigidity and the torque output capacity are improved. The cycloidal pin wheel structure has the characteristic of high bearing capacity, and the input rotating speed is improved by using a symmetrical design, so that the structural power is improved. In the design case, the working performance of more than 600W and more than 30Nm is realized under the conditions that the mass is less than 175g and the thickness is about 16 mm.

Drawings

FIG. 1 is an isometric view of the present invention.

Figure 2 is a cross-sectional view of the present invention.

Fig. 3 is an exploded view of the input eccentric generator of the present invention.

Fig. 4 is a schematic diagram of the input eccentricity generator of the present invention.

Fig. 5 is an isometric view of a portion of the disk-type cycloidal pin gear speed reduction structure of the present invention.

Fig. 6 is a partial exploded view of the disk type cycloidal pin gear speed reducing structure of the present invention.

Fig. 7 is an isometric view of a portion of the mounting structure of the present invention.

Fig. 8 is an exploded view of a portion of the mounting structure of the present invention.

Figure 9 is a schematic drawing showing the tangency of the peripheral rollers and the cycloidal disk of the present invention.

In the drawings:

1-inputting an eccentric generator, 2-a disc type cycloidal pin gear speed reducing structure, 3-an installation structure and 4-a rear driving motor; 5-torque input screw, 6-motor mounting plate, 7-mounting flange plate, 8-eccentric generating bearing, 9-first gasket and 10-eccentric generating bearing mounting pin; 11-cycloidal wheel disc, 12-copper column, 13-peripheral roller, 14-roller mounting pin, 15-output bearing, 16-second gasket, 17-upper side mounting pin fixing flange ring, 18-lower side mounting pin fixing flange ring, and 19-output bearing retaining ring; 20-output bearing, 21-output flange ring, 22-third gasket, 23-torque output screw, 24-mounting flange ring and 25-structure assembly screw.

Detailed Description

The technical scheme of the invention is further specifically described by the following embodiments and the accompanying drawings.

Example (b):

the dimensional conditions and achieved performance of the speed reducer in this example are as follows:

maximum diameter 73mm, thickness 16mm, weight 175g, reduction ratio 23: 1, the maximum input rotating speed is about 10000r/min, the maximum output torque is greater than 30Nm, the maximum output power is greater than 600W, and the efficiency is greater than 90%.

For example, as shown in fig. 1 and 2, a thin cycloidal pin gear reducer of the present invention includes a reducer body and a rear drive motor 4. The speed reducer main body is composed of an input eccentric generator 1, a disc type cycloidal pin gear speed reducing structure 2 and a mounting structure 3. The rear driving motor 4 is installed by a torque input screw 5 penetrating through the input eccentric generator, and is fixed by a plurality of penetrating structural assembly screws 25 and a motor mounting plate 6 which are installed on the rear driving motor. The input eccentric generator 1 and the disc type cycloid pin gear speed reducing structure 2 are located at the same position on the horizontal height, the mounting structure 3 is located on the upper side of the disc type cycloid pin gear speed reducing structure 2, and the driving motor is located on the lower side of the disc type cycloid pin gear speed reducing structure 2.

The input eccentric generator 1 is shown in fig. 3, and comprises flange plates 7 at the upper side and the lower side, six sets of eccentric generating bearing mounting pins 10 with different mounting modes, an eccentric generating bearing 8 and a first gasket 9 assembly. Proper selection of the specification of the gasket can enable the flange sides of the eccentric bearing 8 in the six assemblies which are installed in the front and the back to be located at the same height, and the flange sides are used for separating the two cycloid discs 11 to prevent friction. The end of the combined body is fixed in the blind holes of the flange plates 7 at the upper side and the lower side. The installation modes of two non-adjacent combinations are opposite, the specific position structure is shown in fig. 4, each non-adjacent three combinations determine a circle, the center of the circle has an offset relative to the rotation center, the offset directions of the corresponding centers of the two combinations are opposite, an eccentric input structure required by the disc type cycloidal pin gear speed reducing structure 2 is formed, and two groups of symmetrical eccentric swings can be generated by inputting the eccentric generator 1 to rotate around the geometric center of the eccentric generator. The flange plate 7 is provided with a fixing hole for mounting the motor, and the fixing hole penetrates through a screw to be assembled with the motor, so that the input eccentric generator 1 is fastened. Compared with the traditional crankshaft mode, the input eccentric generator 1 only has extremely small rotating unbalanced mass when rotating, and the stability of high-speed operation can be ensured.

The disk-type cycloidal pin wheel speed reducing structure 2 is characterized in that an axonometric view is shown in fig. 5, a structural explosion view is shown in fig. 6, and the structure comprises a cycloidal wheel disk 11, a copper column 12, a peripheral roller 13, a roller mounting pin 14, an upper side mounting pin fixing flange ring 17, a lower side mounting pin fixing flange ring 18, an output bearing 15, an output bearing retaining ring 19 and a second gasket 16. The input eccentric generator 1 is mounted between two cycloid discs 11 for generating an eccentric motion. The roller mounting pins 14 are mounted and fixed through the uniformly distributed holes in the upper mounting pin fixing flange ring 17 and the lower mounting pin fixing flange ring 18, and the peripheral rollers 13 are mounted on the roller mounting pins 14 and are restricted from axial movement by the upper mounting pin fixing flange ring 17 and the lower mounting pin fixing flange ring 18. Wherein the upper mounting pin fixing flange ring 17 has an inner flange structure for fixing the output bearing 20. The cycloid wheel disc 11 is symmetrically arranged in the space surrounded by the peripheral roller 13, the outer contour of the cycloid wheel disc is tangent with the peripheral roller 13, as shown in fig. 9, the inner center circular hole of the cycloid wheel disc is tangent with the same group of three eccentric generating bearings 8 of the input eccentric generator 1 at the same time, the copper column 12 is penetrated by a structural assembly screw 25 and fixedly arranged between the upper side mounting pin fixing flange ring 17 and the lower side mounting pin fixing flange ring 18 for keeping the movement space of the cycloid wheel disc 11. A plurality of uniformly distributed through holes for torque output are formed in the cycloid wheel disc 11, output bearing bearings 15 are arranged in the through holes, the bearings are tangent to the two cycloid wheel discs 11 at the same time, and swing of the cycloid wheel discs 11 is converted into rotary motion. And second gaskets 16 are arranged on two sides of the output bearing 15 to ensure the rotation stability and the matching position of parts. The torque output screw 23 passes through the output flange ring 21, the output bearing 15, the second gasket 16, the output bearing retaining ring 19 and the output flange ring 21, is relatively fixed, is fixed through a nut, and outputs torque outwards. The output bearing retaining ring 19 improves the rigidity of the output structure. The peripheral rollers 13 and the roller mounting pins 14 in the disc-type cycloidal pin wheel speed reducing structure 2 adopt ceramic ball design, so that the volume of the pin wheel part is reduced to the maximum extent, the speed reducing ratio is improved to the maximum extent, and the output torque is improved. The structural part in this example is only about 13mm, with a torque output capacity of more than 30 Nm. The cycloid wheel disc is small in mass, close to installation and small in structural operation vibration.

The mounting structure 3, shown in isometric view in fig. 7 and exploded view in fig. 8, includes an output flange ring 21, a mounting flange ring 24, an output bearing 20, a torque output screw 23, a structural assembly screw 25, and a third spacer 22. An output flange ring 21 is arranged on the inner side of the output bearing 20, a plurality of threaded holes are formed in two groups, and one group of output flange threaded holes are used for installing an output structural member. The axial positioning of the output flange ring 21 is ensured by the third gasket 22 and the second gasket 16. The other group is the mounting holes for the torque output screws 23 for the transmission of the torque generated by the cycloid discs 11. The outer side of the output bearing 20 is provided with a mounting flange ring 24, and the same mounting flange ring is also provided with two groups of threaded holes with a plurality of numbers, one group is used for external mounting, and the other group is used for fixing the cycloidal pin gear speed reducing structure 2 and mounting and fixing the rear driving motor 4. Flanges are arranged on the mounting flange ring 24 and the mounting pin fixing flange ring 17 to ensure the axial positioning of the output bearing 20.

The working process of the embodiment is as follows:

the rotary motion of motor transmits for input eccentric generator 1 through moment input screw 5, input eccentric generator 1 is tangent with two cycloid wheel dishes 11 respectively, convert the rotary motion of motor into the rotatory swing of cycloid wheel dish 11, the protruding tooth of cycloid wheel dish 11 is sunken in the recess that peripheral ceramic roller 13 constitutes, the number of groove ratio rim plate teeth is 1 more, when 11 rotatory rounds of cycloid wheel dishes, cycloid wheel dish 11 is one check for peripheral ceramic roller 13 dislocation, realize the speed reduction effect promptly, the speed reduction ratio equals the rim plate teeth number. The rotary swing of the cycloid wheel disc is converted into rotary motion through the tangential matching with the output bearing 15, and the output bearing 15 is fixedly connected with the output flange ring 21 to output torque outwards.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments, or alternatives may be employed, by those skilled in the art, without departing from the spirit or ambit of the invention as defined in the appended claims.

Claims

1. A thin cycloidal pin gear speed reducer is characterized in that: the device comprises an input eccentric generator, a disc type cycloid pin wheel speed reducing structure, a mounting structure and a rear driving motor; wherein the content of the first and second substances,

2. The thin cycloidal pin gear reducer of claim 1 wherein the input eccentricity generator comprises a mounting flange plate, an eccentricity generating bearing mounting pin, an eccentricity generating bearing, a plurality of first spacers; two ends of an eccentric generating bearing mounting pin are respectively fixed on the mounting flange plates at the upper side and the lower side, and an eccentric generating bearing and the first gasket are both mounted on the eccentric generating bearing mounting pin; the eccentric generating bearings are divided into two groups, are oppositely and symmetrically arranged from top to bottom and are respectively in a same circle, and the installation height of the eccentric generating bearings is adjusted through a first gasket, so that the flange edges of the two groups of eccentric generating bearings are positioned at the same height.

3. The thin cycloidal pin gear reducer according to claim 2, wherein the disk cycloidal pin gear reducer comprises two cycloidal wheel discs, a plurality of roller mounting pins, peripheral rollers corresponding to the roller mounting pins, an upper mounting pin fixing flange ring and a lower mounting pin fixing flange ring, wherein two ends of the roller mounting pins are respectively fixed on the upper mounting pin fixing flange ring and the lower mounting pin fixing flange ring, the peripheral rollers mounted on the mounting pins are in tangential fit with the cycloidal wheel discs, and the peripheral rollers form a rotating space of the cycloidal wheel discs; the cycloid wheel disc is arranged between the upper side mounting pin fixing flange ring and the lower side mounting pin fixing flange ring; through holes are uniformly distributed on the cycloid discs, output bearing bearings are arranged in the through holes, and the output bearing bearings are simultaneously tangent to the two cycloid discs and used for outputting torque outwards.

4. The thin-type cycloidal pin gear reducer according to claim 2, wherein a flange edge of the eccentric generating bearing of the cycloidal disk is used for separating two cycloidal disks, and an inner hole of the cycloidal disk is tangent to the eccentric generating bearing of the cycloidal disk.

5. The thin cycloidal pin gear reducer of claim 1 wherein the mounting structure includes an output flange ring, a mounting flange ring, an output bearing;

an output flange ring is arranged on the inner side of the output bearing, an output flange threaded hole is formed in the output flange ring, torque is output outwards, an installation flange ring is arranged on the outer side of the output bearing, and an installation flange threaded hole and an assembly flange threaded hole are formed in the installation flange ring; the mounting flange threaded hole is used for mounting a speed reducer, and the mounting flange threaded hole is used for being fixedly connected with the disc type cycloidal pin gear speed reducing structure.

6. The thin cycloidal pin gear reducer according to claim 5, further comprising torque output screws and structural assembly screws, wherein the output flange ring has two sets of a plurality of threaded holes, one set of the output flange threaded holes is used for mounting an output structural member, the other set is a mounting hole for the torque output screws, and the other end of the torque output screws penetrates through the output flange ring and an output bearing; the structural assembling screws sequentially penetrate through the mounting flange ring, the upper side mounting pin fixing flange ring and the lower side mounting pin fixing flange ring.