CN212839248U

CN212839248U - High-precision miniature speed reducer

Info

Publication number: CN212839248U
Application number: CN202020919637.1U
Authority: CN
Inventors: 张立华; 舒康; 王梓鑫
Original assignee: Shaanxi Changkong Gear Co ltd
Current assignee: Shaanxi Changkong Gear Co ltd
Priority date: 2020-05-27
Filing date: 2020-05-27
Publication date: 2021-03-30
Anticipated expiration: 2030-05-27

Abstract

A high-precision miniature speed reducer comprises a central gear shaft, a pinion and an inner gear ring, wherein the central gear shaft, the pinion and the inner gear ring are arranged in a shell and are used for input and output, the inner gear ring is a flexible inner gear ring, the flexible inner gear ring is of a cup-shaped structure, and an output shaft is arranged in the central position of the outer side of a cup bottom; the shaft lever of the central gear shaft is sleeved with an end cover through a bearing, and the end cover is fixed at the end part of the shell; the pinion is respectively meshed with the central gear and the flexible inner gear ring on the central gear shaft; the pinion is positioned on the end cover through a shaft pin, the shaft pin is fixed with the end cover and is in clearance fit with the pinion, and the pinion can rotate on the shaft pin; and a space is reserved between the outer wall of the flexible annular gear and the inner wall of the shell. Due to the adoption of the flexible inner gear ring, when the meshing gap between the flexible inner gear ring and the pinion is zero or negative, the flexible inner gear ring can generate slight deformation, so that the pinion and the flexible inner gear ring are always in zero-gap meshing. So as to meet the requirement that the return difference can be less than or equal to 6' under the condition that the diameter of the structure is less than 40 mm.

Description

High-precision miniature speed reducer

Technical Field

The utility model belongs to the technical field of the reduction gear, specifically be a miniature reduction gear with high accuracy.

Background

The application of the existing speed reducer gradually tends to the development of high precision, low return difference and miniaturization. The high precision and low return difference performance of the product are established on the basis of high precision of part machining, and only when the precision of parts is improved, the tooth part and other fit clearances can be correspondingly reduced, so that the motion precision of the speed reducer is improved, and the return difference is reduced. When the diameter size of the product structure of the existing speed reducer is larger than 60mm and the transmission ratio is smaller than 30, the product precision can be achieved by improving the part machining precision and the anti-backlash gear transmission. The return difference can be less than or equal to 6 'and even less than or equal to 3' by the prior process. If the transmission ratio of the speed reducer is greater than 30, the product precision can be realized in a harmonic transmission or RV transmission mode. However, for a miniature speed reducer with a structure smaller than 40mm, the return difference is less than or equal to 6 'and more difficult to achieve, and the return difference is less than or equal to 3'. Even if the backlash is forcibly reduced, the precision of parts cannot be well matched due to the limitation of the existing processing capacity, so that local interference is caused, and the problems of unsmooth operation, low efficiency, serious heating, difficulty in maintaining the precision and the like of the speed reducer can occur.

Disclosure of Invention

In view of this, the utility model provides a high accuracy miniature reduction gear can be under the condition that the structure diameter is less than 40mm, reaches the requirement that the return difference is less than or equal to 6'.

The utility model adopts the technical proposal that: a high-precision miniature speed reducer comprises a central gear shaft, a pinion and an inner gear ring, wherein the central gear shaft and the pinion are arranged in a shell and used for input, the inner gear ring is used for output, and the miniature speed reducer is characterized in that: the inner gear ring is a flexible inner gear ring which is of a cup-shaped structure, and an output shaft is arranged at the center of the outer side of the cup bottom; an end cover is sleeved on the shaft lever of the central gear shaft through a bearing, and the end cover is fixed at the end part of the shell; the pinion is respectively meshed with the gear on the central gear shaft and the flexible inner gear ring; the pinion is positioned on the end cover through a shaft pin, the shaft pin is fixed with the end cover and is in clearance fit with the pinion, and the pinion can rotate on the shaft pin; and a space is reserved between the outer wall of the flexible inner gear ring and the inner wall of the shell.

Furthermore, the shaft lever of the shaft pin is of a double-flat structure, two parallel and symmetrical sections are arranged on the shaft lever of the shaft pin, the sections are parallel to the axis of the shaft pin, and the distance from the axis of the shaft lever to the sections is smaller than the distance from the axis of the shaft lever to the circumference of the shaft lever.

Further, the cross section of the shaft pin is perpendicular to the radial force applied to the pinion.

Further, the number of the pinions is two.

The utility model has the advantages that: due to the adoption of the flexible inner gear ring, when the meshing gap between the flexible inner gear ring and the pinion is zero or negative, the flexible inner gear ring can generate slight deformation in the radial direction, so that the pinion and the flexible inner gear ring are always in zero-gap meshing. So as to meet the requirement that the return difference can be less than or equal to 6' under the condition that the diameter of the structure is less than 40 mm.

And because the shaft pin is arranged into a double-flat structure, the floating amount of the pinion is increased under the condition that the fit clearance between the shaft pin and the inner hole of the axle center of the pinion is not changed, and the clamping stagnation possibly caused by the deformation of the flexible inner gear ring in the running process of the planetary gear is avoided.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a schematic structural view of the middle flexible ring gear of the present invention.

Fig. 3 is a schematic diagram of the effect of slight deformation of the flexible annular gear.

Fig. 4 is a schematic structural view of the shaft pin of the present invention.

Fig. 5 is a left side view of fig. 4.

Fig. 6 is a schematic view of an assembly structure of the shaft pin and the pinion.

In the figure: 1. the gear comprises a central gear shaft, 2, a bearing, 3, a shaft pin, 3-1, a cross section, 4, an end cover, 5, a screw, 6, a pinion, 7, a shell, 8, a flexible inner gear ring, 9 and a bearing.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the present invention will be further described in detail with reference to the accompanying drawings and specific embodiments.

As shown in fig. 1, a high-precision micro reduction gear includes planetary gears provided in a housing 7. The planetary gear includes a sun gear shaft 1 for input, a pinion gear 6, and an inner gear ring for output. The pinion gears 6 are two and are engaged between the sun gear and the inner gear ring at equal intervals. As shown in fig. 2, the ring gear is a flexible ring gear 8. The flexible inner gear ring 8 is of a cup-shaped structure. The cup wall is provided as a thin-walled component that can be slightly deformed. The central gear shaft 1 is coaxially connected with the bottom of the cup-shaped inner side of the flexible inner gear ring 8 through a bearing 9, and an output shaft is arranged at the central position of the cup-shaped outer side of the flexible inner gear ring 8. And a space is reserved between the outer wall of the flexible inner gear ring 8 and the inner wall of the shell 7, and the space is larger than the deformation of the flexible inner gear ring 8. An end cover 4 is sleeved on the shaft rod of the central gear shaft 1 through a bearing 2. The end cap 4 is fixed to the end of the housing 7 by screws 5. The end cap 4 also serves as a planet carrier. The two pinions 6 are each positioned on the end caps 4 by means of a shaft pin 3. The shaft pin 3 passes through the center position of the pinion 6 and is fixed with the end cover 4. The shaft pin 3 is in clearance fit with the pinion 6, and the pinion 6 can rotate on the shaft pin 3.

As shown in fig. 3, when the meshing gap between the flexible ring gear 8 and the pinion 6 is zero or negative, the flexible ring gear 8 is slightly deformed in the radial direction. Just because of the deformation of the flexible inner gear ring 8, the pinion 6 and the flexible inner gear ring 8 are always in zero-clearance engagement. And because the central gear shaft 1 is used as an input shaft and the flexible inner gear ring 8 is used for transmitting power through the pinion 6, the requirement that the speed reducer is coaxial in input and output within the range of 20-40mm is met. To sum up, the utility model discloses reached under the condition that the structure diameter is less than 40mm, the purpose that the return difference can be less than or equal to 6'.

Since the radial force to which the flexible annular gear 8 is subjected to deformation is exerted by the pinion 6, a possible jamming of the planet gears during operation is avoided. The shaft pin 3 on the pinion 6 is structurally improved.

As shown in fig. 4 to 6, the shaft of the shaft pin 3 is provided in a double-flat structure. That is, two parallel and symmetrical sections 3-1 are provided on the shaft of the shaft pin 3. The section 3-1 is parallel to the axis of the pin 3. The distance from the shaft axis to the section 3-1 is smaller than the distance to the shaft circumference. As is clear from fig. 6, the clearance between the inner bore of the pinion 6 and the outer diameter of the shaft pin 3 in the x direction is larger than the clearance in the y direction. Due to the double-flat structure of the shaft pin 3, under the condition that the fit clearance between the shaft pin and the inner hole of the pinion 6 is not changed, the radial floating amount of the planet wheel is increased, so that clamping stagnation is avoided, and the normal rotation of the planet wheel is ensured. It should be noted that the section 3-1 on the shaft pin 3 is perpendicular to the radial force to which the pinion 6 is subjected. Taking fig. 6 as an example, the radial force to which the pinion 6 is subjected is in the X direction.

Claims

1. A high-precision miniature speed reducer comprises a central gear shaft, a pinion and an inner gear ring, wherein the central gear shaft, the pinion and the inner gear ring are arranged in a shell and used for input, and the inner gear ring is used for output, and is characterized in that: the inner gear ring is a flexible inner gear ring which is of a cup-shaped structure, and an output shaft is arranged at the center of the cup bottom; an end cover is sleeved on the shaft lever of the central gear shaft through a bearing, and the end cover is fixed at the end part of the shell; the pinion is respectively meshed with the gear on the central gear shaft and the flexible inner gear ring; the pinion is positioned on the end cover through a shaft pin, the shaft pin is fixed with the end cover and is in clearance fit with the pinion, and the pinion can rotate on the shaft pin; and a space is reserved between the outer wall of the flexible inner gear ring and the inner wall of the shell.

2. A high-precision miniature speed reducer according to claim 1 wherein: the shaft lever of the shaft pin is of a double-flat structure, two parallel and symmetrical sections are arranged on the shaft lever of the shaft pin, the sections are parallel to the axis of the shaft pin, and the distance from the axis of the shaft lever to the sections is smaller than the distance from the axis of the shaft lever to the circumference of the shaft lever.

3. A high-precision miniature speed reducer according to claim 2 wherein: the cross section of the axle pin is perpendicular to the radial force applied to the pinion.

4. A high-precision miniature speed reducer according to claim 1 wherein: the number of the pinions is two.