WO2021008060A1

WO2021008060A1 - Planetary decelerator

Info

Publication number: WO2021008060A1
Application number: PCT/CN2019/121390
Authority: WO
Inventors: 蒋剑; 李学志
Original assignee: 苏州小工匠机器人有限公司
Priority date: 2019-07-16
Filing date: 2019-11-28
Publication date: 2021-01-21
Also published as: CN110242711A

Abstract

A planetary decelerator, comprising a sun gear (10), at least two planetary gears (20) engaged with the sun gear (10), a planet carrier (30) connected to each planetary gear (20), an inner ring gear (40) engaged with each planetary gear (20), and a ring gear fixing base (50) sleeved on the periphery of the inner ring gear (40). An input shaft (11) is further provided at the center of the sun gear (10). An output shaft (31) coaxial to the input shaft (11) is provided at the center of the planet carrier (30). Elastic members (60) are further provided between the inner ring gear (40) and the ring gear fixing base (50) so as to provide the elastic force for the inner ring gear (40) in the radial direction. The planetary decelerator can eliminate the matching clearance between the inner ring gear and the planetary gear, and between the planetary gear and the sun gear, and eliminate the backlash.

Description

Planetary reducer

Technical field

The invention relates to the field of reducer equipment, in particular to a planetary reducer.

Background technique

At present, in the field of reducer equipment, planetary reducers are widely used in servo motors, stepping motors and other transmission systems due to their small size, high transmission efficiency, wide reduction range, and high precision. The main transmission structure of the planetary gear reducer is: planetary gear, sun gear, ring gear and planet carrier. At present, the main reason that affects the accuracy of the planetary reducer is the backlash caused by the gear manufacturing accuracy. Backlash is the return gap: when the output end is fixed, the input end rotates clockwise and counterclockwise to make the input end produce rated torque +/-2% torque, there is a slight angular displacement at the input end of the reducer, this angular displacement is The unit of return gap is: arc minutes, which is one sixtieth of a degree. The lower the value of this return clearance, the better, and the corresponding planetary reducer is also more expensive. The current planetary reducer with higher precision is very expensive.

Summary of the invention

The object of the present invention is to provide a planetary reducer.

In order to achieve the above-mentioned object of the invention, an embodiment of the present invention provides a planetary reducer, including a sun gear, at least two planet gears meshingly connected with the sun gear, and a planet carrier connected with each of the planet gears, An inner gear ring meshingly connected with each of the planet gears, and a gear ring fixing seat sleeved on the outer circumference of the inner gear ring; the center of the sun gear is also provided with an input shaft, and the center of the planet carrier is provided There is an output shaft coaxial with the input shaft; an elastic element is also provided between the inner gear ring and the gear ring fixing seat to provide the inner gear ring with elastic force in the radial direction.

As a further improvement of the present invention, the planetary reducer is provided with a plurality of the elastic elements, and the plurality of elastic elements are arranged on the outer circumference of the inner gear at intervals along the circumferential direction of the inner gear.

As a further improvement of the present invention, there is a gap between each of the elastic elements, and the size of the gap ranges from 1 mm to 3 mm. As a further improvement of the present invention, the elastic element is annular, and the elastic element is arranged around the outer circumference of the inner gear ring.

As a further improvement of the present invention, the material of the elastic element is polyurethane elastomer.

As a further improvement of the present invention, the surface of the elastic element facing the inner gear ring is provided with a groove, and the outer circumference of the inner gear ring is clamped in the groove.

As a further improvement of the present invention, the width of the groove is smaller than the size of the inner gear ring in the axial direction.

As a further improvement of the present invention, the surface of the ring gear holder facing the elastic element is provided with a plurality of protrusions; the protrusions are pressed against the elastic element.

As a further improvement of the present invention, the planet carrier includes a carrier body and at least two connecting parts extending from the carrier body, each of the connecting parts is respectively connected to the planetary wheel; each of the connecting parts is connected to A relief groove is provided at the position where the frame body is combined, and the relief groove is a through groove that penetrates the planet carrier in the axial direction.

As a further improvement of the present invention, the relief groove is an arc-shaped through groove extending along the circumferential direction of the frame body.

Compared with the prior art, in the planetary reducer disclosed in the present invention, an elastic element is added between the inner ring gear and the ring gear fixing seat. The elastic element is easily deformed in the radial direction, so that after the planetary reducer is assembled, the ring gear The fixed seat squeezes the inner gear ring to tightly mesh with the planetary gear through the elastic element, and then the planet gear and the sun gear are tightly meshed together, thereby eliminating the matching gap between the inner gear ring and the planet gear, as well as the planet gear and the sun gear. And eliminate the return gap. The planetary reducer of the present invention has a simple structure, low cost, and has a better effect of eliminating backlash.

Description of the drawings

FIG. 1 is a schematic diagram of the structure of a planetary reducer in an embodiment of the present invention;

2 is a schematic diagram of a part of the structure of a planetary reducer in an embodiment of the present invention;

3 is a schematic diagram of a part of the structure of a planetary reducer in another embodiment of the present invention;

4 is a schematic diagram of an exploded structure of an elastic element and an inner gear ring in an embodiment of the present invention;

Fig. 5 is a schematic structural diagram of a ring gear holder in an embodiment of the present invention;

Fig. 6 is a schematic structural diagram of a planet carrier in an embodiment of the present invention.

Detailed ways

The present invention will be described in detail below in conjunction with the specific embodiments shown in the drawings. However, these embodiments do not limit the present invention, and the structural, method, or functional changes made by those skilled in the art based on these embodiments are all included in the protection scope of the present invention.

It should be understood that terms such as "upper", "above", "below", "below" and the like used herein to indicate a relative position in space are for the purpose of facilitating explanation to describe a unit or feature as shown in the accompanying drawings. Relationship to another unit or feature. The term of the relative position in space may be intended to include different orientations of the device in use or operation other than those shown in the figures.

As shown in Figures 1-6, an embodiment of the present invention discloses a planetary reducer, including a sun gear 10, at least two planet gears 20 meshingly connected with the sun gear 10, and each of the planet gears A planet carrier 30 connected to each of the planet gears 20, an inner gear ring 40 meshingly connected with each of the planet wheels 20, and a ring gear fixing seat 50 sleeved on the outer circumference of the inner gear ring 40. An elastic element 60 is also provided between the inner gear 40 and the gear holder 50 to provide the inner gear 40 with elastic force in the radial direction.

Specifically, the center of the sun gear 10 is also provided with an input shaft 11, which is connected to the motor to provide driving force; the center of the planet carrier 30 is provided with an output shaft 31 coaxial with the input shaft 11, and the output shaft 31 can be connected to the equipment that needs to be driven, and the output of the motor is reduced by the planetary reducer to reduce the transmission speed, and output to the equipment to drive the equipment to run.

In the embodiment of the present invention, the sun gear 10, the planet gears 20 and the ring gear 40 are all gears, wherein the sun gear 10 and the planet gears 20 are gears with teeth provided on the outside, and the ring gear 40 is a gear with teeth provided on the outside. Internal internal gear.

In the planetary reducer disclosed in the present invention, an elastic element 60 is added between the inner ring gear 40 and the ring gear holder 50. The elastic element 60 is easily deformed in the radial direction, so that after the planetary reducer is assembled, the ring gear holder 50 The inner ring gear 40 is squeezed by the elastic element 60 to tightly mesh with the planet gear 20, and the planet gear 20 and the sun gear 10 are closely meshed together, thereby eliminating the inner gear 40 and the planet gear 20, and the planet gear 20 and the sun gear The fit clearance between 10 and eliminate the return clearance. The planetary reducer of the present invention has a simple structure, low cost, and has a better effect of eliminating backlash.

As shown in Figure 2, the planetary reducer is provided with a plurality of the elastic elements 60, and the plurality of elastic elements 60 are arranged on the outer circumference of the inner ring gear 40 at intervals along the circumferential direction of the ring gear 40 . The elastic element 60 is set as a plurality of arc-shaped strips, which is convenient to manufacture and easy to install.

Further, there is a gap between each of the elastic elements 60, and the size of the gap ranges from 1 mm to 3 mm. There is a gap between the plurality of elastic elements 60 to allow the elastic element 60 to have a space for deformation.

In the embodiment of the present invention, the material of the elastic element 60 is polyurethane elastomer. Polyurethane elastomer is also called Youli Glue. It is a new type of material with good strength, small compression deformation, and between plastic and rubber. It has the rigidity of plastic and the elasticity of rubber.

As shown in FIG. 3, in another embodiment, the elastic element 60 may also be annular, and the elastic element 60 may be arranged around the outer circumference of the ring gear 40. Specifically, the elastic element 60 is arranged around one circumference of the ring gear 40.

As shown in FIG. 4, the surface of the elastic element 60 facing the inner gear 40 is provided with a groove 61, and the outer circumference of the inner gear 40 is clamped in the groove 61. The elastic element 60 is fixed on the inner gear 40 by clamping the outer periphery of the inner gear 40 in the groove 61. The fixing method is simple and convenient, and no additional fixing elements are required.

Preferably, the width of the groove 61 is smaller than the size of the ring gear 40 in the axial direction. Therefore, the elastic element 60 can be interference fit with the ring gear 40 to provide the ring gear 40 with sufficient elastic force in the radial direction. During installation, because the elastic element 60 has elasticity, the groove 61 can be expanded to wrap the outer circumference of the ring gear 40 in the groove 61 of the elastic element 60. Specifically, the difference between the width of the groove 61 and the size of the ring gear 40 in its own axial direction (that is, the interference size) is approximately between 0.2 mm and 0.3 mm. The outer circumference of 40 can also be tightly connected with the ring gear 40 at the same time.

Furthermore, as shown in FIG. 5, the surface of the ring gear holder 50 facing the elastic element 60 is provided with a plurality of protrusions 51, and the protrusions 51 are pressed against the elastic element 60. A protrusion 51 is provided on the ring gear holder 50, which can further press the elastic element 60 to further provide the inner ring gear 40 with elastic force in the radial direction.

As shown in FIG. 6, in the embodiment of the present invention, the planet carrier 30 includes a carrier body 32 and at least two connecting portions 33 extending from the carrier body 32, and each connecting portion 33 is connected to the The central axis of the planet wheel 20 is fixedly connected; each position where the connecting portion 33 is combined with the carrier body 32 is provided with a relief groove 331, and the relief groove 331 is a through groove that penetrates the planet carrier 30 in the axial direction . The provision of the relief groove 331 on the planet carrier 30 is mainly to enable the elastic element 60 to impart elastic force to the ring gear 50 in the radial direction, and the planet carrier 30 can generate a small amount of deformation due to the existence of the relief groove 331, thereby transmitting the elastic force To the planetary gear 20, the planetary gear 20 can mesh closely with the sun gear 10, and finally the clearance between the planetary gear 20 and the sun gear 10 is eliminated, and the return clearance is eliminated. Specifically, depending on the shape, size, and number of the relief grooves 331, the amount of slight deformation of the planet carrier can be set to 0.05 mm to 0.25 mm. In the embodiment of the present invention, the slight deformation of the planet carrier is 0.1 mm.

In another embodiment, an elastic material can be provided at the bearing of the planetary gear 20, so that the planetary gear 20 can also be directly deformed in the radial direction, so that the planetary gear 20 and the sun gear 10 are closely meshed together.

In the embodiment of the present invention, two planetary gears 20 are provided on the planetary reducer. In other embodiments, three or more planetary gears may also be provided.

As shown in FIG. 1, in fact, the embodiment of the present invention includes two planet carriers 30, each planet carrier has a corresponding carrier body and a connecting part, and the planetary wheels are connected to the planetary wheels at both ends in the axial direction of the planetary wheels. An output shaft 31 is provided on one of the planet carriers. In other embodiments, there may be one planet carrier, or two planet carriers may be integrally formed.

Specifically, the material of the planet carrier can be 20Cr steel. Of course, in other embodiments, the material of the planet carrier can also be other hard metal materials.

As shown in FIG. 6, the relief groove 331 is an arc-shaped through groove extending along the circumferential direction of the frame body 32.

In another embodiment, a plurality of relief grooves 331 may also be provided on the frame body 32, and the shape of the relief grooves may be arc, square or other shapes.

The following describes the assembly method of the planetary reducer in the embodiment of the present invention.

As shown in FIG. 1, first, a plurality of elastic elements 60 are sequentially installed on the outer circumference of the inner gear 40, that is, the groove of the elastic element 60 is connected with the inner gear 40 by interference fit; and then the ring gear holder 50 It is connected with the elastic element 60 by interference fit, so that the elastic element 60 is tightly pressed between the ring gear fixing seat 50 and the inner ring gear 40. Next, the two planet wheels 20 are assembled with the planet carrier 30 respectively. That is, the connecting portion 33 is fixedly connected with the pin shaft provided in the center of the planetary gear; then, the planetary gear 20 and the sun gear 10 are installed together, and the two planetary gears 20 are meshed with the sun gear 10 respectively, and the sun gear 10 is located between the two planet wheels 20. Finally, the installed ring gear 40 is meshedly connected to the two planet wheels 20, and the ring gear 40 encloses the two planet wheels 10 inside. Finally, install the motor and its end cover at a suitable position.

In the planetary reducer disclosed in the present invention, an elastic element is added between the inner gear ring and the ring gear fixing seat. The elastic element is easily deformed in the radial direction, so that after the planetary reducer is assembled, the ring gear fixing seat is squeezed by the elastic element The inner ring gear closely meshes with the planet gears, and then the planet gears and the sun gear are closely meshed together, thereby eliminating the matching clearance between the inner gear ring and the planet gear, as well as the planet gear and the sun gear, and eliminating the return clearance. The planetary reducer of the present invention has a simple structure, low cost, and has a better effect of eliminating backlash. The elastic element is a plurality of arc-shaped strips, and a gap is left between the plurality of elastic elements, so that the elastic element can have a space for deformation. The material of the elastic element is polyurethane elastomer, which has the rigidity of plastic and the elasticity of rubber. The elastic element can be an interference fit with the inner gear ring to provide sufficient elastic force in the radial direction. A protrusion is provided on the gear ring fixing seat, and the elastic element 60 is further compressed to further provide elastic force for the inner gear ring in the radial direction. The connecting part on the planet carrier and the carrier body are equipped with relief grooves that penetrate the planet carrier, so that when the elastic element imparts elastic force to the ring gear in the radial direction, the planet carrier can generate a small amount of deformation due to the existence of the relief groove. , So as to transmit the elastic force to the planetary gears, so that the planetary gears can be closely meshed with the sun gear, and finally eliminate the matching clearance between the planetary gear and the sun gear, and eliminate the return clearance.

It should be understood that although this specification is described in accordance with the implementation manners, not each implementation manner only includes an independent technical solution. This narration in the specification is only for clarity, and those skilled in the art should regard the specification as a whole. The technical solutions in the embodiments can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

The series of detailed descriptions listed above are only specific descriptions of feasible implementations of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementations or implementations made without departing from the technical spirit of the present invention All changes shall be included in the protection scope of the present invention.

Claims

A planetary reducer, characterized in that it comprises a sun gear, at least two planet gears meshingly connected with the sun gear, a planet carrier connected with each planet gear, and each planet gear. The inner gear ring that is meshingly connected, and the gear ring fixing seat sleeved on the outer circumference of the inner gear ring;

The center of the sun gear is also provided with an input shaft, and the center of the planet carrier is provided with an output shaft coaxial with the input shaft;

An elastic element is also provided between the inner gear ring and the gear ring fixing seat to provide the inner gear ring with elastic force in the radial direction.
The planetary reducer according to claim 1, wherein a plurality of the elastic elements are provided on the planetary reducer, and the plurality of elastic elements are arranged at intervals along the circumferential direction of the ring gear. The outer circumference of the inner ring gear.
The planetary reducer according to claim 2, wherein each of the elastic elements has a gap, and the size of the gap ranges from 1 mm to 3 mm.
The planetary reducer according to claim 1, wherein the elastic element is annular, and the elastic element is arranged around the outer circumference of the inner gear ring.
The planetary reducer according to claim 1, wherein the material of the elastic element is polyurethane elastomer.
The planetary reducer according to claim 2 or 4, wherein the surface of the elastic element facing the ring gear is provided with a groove, and the outer circumference of the ring gear is clamped in the groove.
The planetary reducer according to claim 6, wherein the width of the groove is smaller than the dimension of the ring gear in the axial direction.
The planetary reducer according to claim 1, wherein the surface of the ring gear holder facing the elastic element is provided with a plurality of protrusions; the protrusions are pressed against the elastic element.
The planetary reducer according to claim 1, wherein the planet carrier includes a carrier body and at least two connecting parts extending from the carrier body, and each of the connecting parts is connected to the planetary wheel; A relief groove is provided at each position where the connecting portion is combined with the carrier body, and the relief groove is a through groove that penetrates the planet carrier in the axial direction.
The planetary reducer according to claim 9, wherein the relief groove is an arc-shaped through groove extending along the circumferential direction of the frame body.