CN111828558A

CN111828558A - Adjustable-gap small-tooth-difference speed reducer

Info

Publication number: CN111828558A
Application number: CN202010797624.6A
Authority: CN
Inventors: 宋朝省; 闫国帅; 汪言; 朱才朝; 杜雪松
Original assignee: Chongqing University
Current assignee: Chongqing University
Priority date: 2020-08-10
Filing date: 2020-08-10
Publication date: 2020-10-27
Anticipated expiration: 2040-08-10
Also published as: CN111828558B

Abstract

The invention belongs to the field of transmission, and relates to a gap-adjustable speed reducer with small tooth difference, which comprises a transmission shell and two internal gears, wherein the two internal gears are arranged in the transmission shell through a gap adjusting module, and the tooth thicknesses of the two internal gears are changed; the internal gear is meshed with an external gear with the changed tooth thickness arranged inside the internal gear to form a transmission pair; a small gap is formed between the outer gear and the pin shaft bracket, so that the outer gear and the pin shaft bracket are not contacted with each other, and the outer gear and the pin shaft bracket are connected through a pin shaft column penetrating through the outer gear; the inner side of the external gear is connected to an input crank through a bearing. The invention realizes the transmission requirements of the small-tooth-difference planetary gear transmission without return difference and high precision, and can compensate and eliminate the manufacturing error, the installation error and the tooth side clearance generated by the working abrasion of the transmission device, thereby realizing the precision transmission without backlash and return difference.

Description

Adjustable-gap small-tooth-difference speed reducer

Technical Field

The invention belongs to the field of transmission, and relates to a gap-adjustable small-tooth-difference speed reducer.

Background

The N-type transmission with less tooth difference is widely applied to various industrial fields because of the characteristics of high transmission ratio, compact structure, strong load carrying capacity because of more engaged teeth, and the like, but has more strict requirements on transmission precision and transmission return difference control along with the development of production technology and the requirements of a series of equipment and instruments with accurate positioning requirements, such as medical equipment, robots, military equipment and the like. A backlash elimination device must be introduced to realize zero backlash transmission, and the backlash elimination device can finally determine the precision of the whole speed reducer. Most of the existing gap eliminating devices can affect the strength of a transmission mechanism, the gap adjusting capacity is reduced or the gap adjusting capacity is invalid after long-time work, and the problems of gear backlash and the like caused by installation errors, manufacturing errors and gear abrasion of the transmission mechanism cannot be solved.

Disclosure of Invention

In view of the above, the present invention provides a reducer with adjustable gap and small tooth difference to solve the problem of backlash of a transmission gear pair for N-type transmission with small tooth difference.

In order to achieve the purpose, the invention provides the following technical scheme:

a gap-adjustable speed reducer with small tooth difference comprises a transmission shell and two internal gears, wherein the two internal gears are arranged in the transmission shell through a gap adjusting module, and the tooth thicknesses of the two internal gears are changed; the internal gear is meshed with an external gear with the changed tooth thickness arranged inside the internal gear to form a transmission pair; a small gap is formed between the outer gear and the pin shaft bracket, so that the outer gear and the pin shaft bracket are not contacted with each other, and the outer gear and the pin shaft bracket are connected through a pin shaft column penetrating through the outer gear; the inner side of the external gear is connected to an input crank through a bearing.

Optionally, the pin shaft column is arranged on the pin shaft support through a pin shaft sleeve sleeved outside the pin shaft column, and is connected with the pin shaft support through a pin shaft nut arranged at the end part of the pin shaft column.

Optionally, the transmission housing includes a box body and end covers disposed at two sides of the box body; the transmission pair is arranged in parallel to the end cover.

Optionally, the gap adjusting module includes a gap adjusting nut disposed on the end cover, a gap adjusting bolt passing through the end cover and matching with the gap adjusting nut, and a gap adjusting elastic element disposed between the gap adjusting bolt and the internal gear.

Optionally, the external gear is connected with the input crank through a first angular contact ball bearing.

Optionally, the outer gear is fixed to the first angular contact ball bearing through a thermal expansion method, and the first angular contact ball bearing is fixed to the input crank through an interference fit and a shaft shoulder, and is used for offsetting an axial force generated by the gap adjusting module.

Optionally, steps for fixing and separating the two internal gears are arranged in the transmission shell; an elastic gasket is arranged between the step and the inner gear, and the rigidity of the elastic gasket is smaller than that of the gap adjusting module.

Optionally, the tooth thickness end of the internal gear is in contact engagement with the tooth thickness end of the external gear.

Optionally, the pin shaft supports are connected through a second deep groove ball bearing.

Optionally, two pin shaft brackets are symmetrically arranged in the transmission housing, wherein the pin shaft bracket facing the power input end of the input crank is arranged on the transmission housing through a second angular contact ball bearing, and the other pin shaft bracket is arranged on the transmission housing through a first deep groove ball bearing.

The invention has the beneficial effects that:

1. in the invention, the inner gear with the changed tooth thickness and the outer gear with the changed tooth thickness can be tightly attached together by the axial force applied to the inner gear by the clearance adjusting module, so that the backlash is very small or in a zero backlash state, and the uncertain backlash caused by installation error, manufacturing error and abrasion can be compensated.

2. According to the invention, the pre-tightening force of the clearance adjusting elastic element is applied through the clearance adjusting bolt and the clearance adjusting locking nut, the pre-tightening force of the elastic element required by clearance adjustment can be easily obtained by controlling the screwing length of the clearance adjusting bolt, and in addition, if the elastic element is in a loose state after long-time work, the pre-tightening force of the clearance adjusting elastic element can be readjusted.

3. According to the invention, the two external gears with the changed tooth thicknesses are fixed on the first angular contact ball bearing through thermal expansion, the first angular contact ball bearing is fixed on the input crank through interference fit and the shaft shoulder, and the two end gap adjusting modules can generate reverse axial force to be transmitted to the input crank through the first angular contact bearing to be offset through the connection in such a way, so that the transmission device can run more stably.

4. The box body of the invention is internally provided with steps; an elastic gasket is arranged between the step and the inner gear, the rigidity of the elastic gasket is smaller than that of the gap adjusting module, and the effect of controlling the axial displacement of the inner gear and preventing the two inner gears from moving and interfering with each other is achieved.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the means of the instrumentalities and combinations particularly pointed out hereinafter.

Drawings

For the purposes of promoting a better understanding of the objects, aspects and advantages of the invention, reference will now be made to the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a cross-sectional view of the present invention;

fig. 2 is a sectional view a-a of fig. 1.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention in a schematic way, and the features in the following embodiments and examples may be combined with each other without conflict.

Wherein the showings are for the purpose of illustrating the invention only and not for the purpose of limiting the same, and in which there is shown by way of illustration only and not in the drawings in which there is no intention to limit the invention thereto; to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.

The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar components; in the description of the present invention, it should be understood that if there is an orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", etc., based on the orientation or positional relationship shown in the drawings, it is only for convenience of description and simplification of description, but it is not an indication or suggestion that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes, and are not to be construed as limiting the present invention, and the specific meaning of the terms may be understood by those skilled in the art according to specific situations.

Referring to fig. 1-2, the reference numbers in the figures refer to the following elements: the device comprises a left end cover 1, an elastic gasket 2, a box body 3, a right end cover 4, an external gear 5 with variable tooth thickness, a first deep groove ball bearing 6, a pin shaft bracket 7, a second deep groove ball bearing 8, a first angular contact ball bearing 9, a pin shaft nut 10, a pin shaft sleeve 11, an end cover fixing nut 12, an end cover fixing bolt 13, an internal gear 14 with variable tooth thickness, a gap adjusting elastic element 15, a pin shaft column 16, an input crank 17, a second angular contact ball bearing 18, a gap adjusting locking nut 19 and a gap adjusting bolt 20.

The invention relates to a gap-adjustable small-tooth-difference speed reducer, which comprises: the two internal gears 14 and the two external gears 5 form two gear pairs for meshing motion; the pin shaft column 16 is fixed on the pin shaft bracket 7 through a pin shaft column nut 10 to form a pin shaft output mechanism; the left end cover 1 and the right end cover 4 of the case are connected with the case 3 through bolts to form a gear transmission shell; the gap adjusting bolt 20 penetrates through the chassis end cover 1, the gap adjusting elastic element 15 and the gap adjusting locking nut 19 to form a gap adjusting module.

Specifically, the inner gear 14 and the outer gear 5 are both gears with variable tooth thicknesses, one thin end of each gear is in contact with one thick end of the gear which is meshed with the thin end of the gear, and pre-tightening force applied to the gap adjusting elastic element 15 through the gap adjusting bolt 20 acts on the inner gear 14 with variable tooth thickness, so that gear pairs of the inner gear are tightly attached to achieve a state that the side gap of the gear is very small or zero, and precision transmission without backlash is achieved; two internal gears 14 with variable tooth thicknesses are connected to the case through splines to enable the internal gears to move axially on the case, two external gears 5 with variable tooth thicknesses are fixed on a first angular contact ball bearing 9 through a thermal expansion method, and the first angular contact ball bearing 9 is fixed on an input crank 17 through interference fit and a shaft shoulder to offset axial force introduced by a clearance adjusting module; the middle part of the case is provided with a protruding shaft shoulder, and the two ends are provided with the elastic gaskets 2, so that the axial displacement of the internal gears 14 is controlled, and the mutual motion interference of the two internal gears 14 is avoided.

When the power output mechanism works, power is input through the input crank 17 to drive the two external gears 5 to perform planetary rotation around the two internal gears 14, the pin shaft column 16 in the pin shaft type output mechanism penetrates through pin holes in the two gears, and the pin shaft type output mechanism realizes power output through the planetary rotation of the internal gears 14.

In the embodiment, the two pieces of external gears 5 are supported by the first angular contact ball bearings 9 facing each other, the pin shaft type output mechanism and the input crank 17 are supported by the first deep groove ball bearings 6, the pin shaft type output mechanism and the chassis are supported by the first deep groove ball bearings 6 and the second deep groove ball bearings 18, and each bearing is positioned by a shaft shoulder.

Finally, the above embodiments are only intended to illustrate the technical solutions of the present invention and not to limit the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions, and all of them should be covered by the claims of the present invention.

Claims

1. The adjustable-gap small-tooth-difference speed reducer is characterized by comprising a transmission shell and two internal gears, wherein the two internal gears are arranged in the transmission shell through a gap adjusting module, and the tooth thicknesses of the two internal gears are changed; the internal gear is meshed with an external gear with the changed tooth thickness arranged inside the internal gear to form a transmission pair; a small gap is formed between the outer gear and the pin shaft bracket, so that the outer gear and the pin shaft bracket are not contacted with each other, and the outer gear and the pin shaft bracket are connected through a pin shaft column penetrating through the outer gear; the inner side of the external gear is connected to an input crank through a bearing.

2. The reducer of claim 1, wherein the pin shaft is disposed on the pin shaft bracket through a pin shaft sleeve disposed on an outer portion of the pin shaft, and is connected to the pin shaft bracket through a pin shaft nut disposed on an end portion of the pin shaft.

3. The adjustable gap reducer with few tooth differences as claimed in claim 1, wherein said transmission housing comprises a case and end caps disposed at both sides of said case; the transmission pair is arranged in parallel to the end cover.

4. The reducer of claim 3, wherein the backlash adjusting module comprises a backlash adjusting nut disposed on the end cap, a backlash adjusting bolt passing through the end cap and engaged with the backlash adjusting nut, and a backlash adjusting elastic element disposed between the backlash adjusting bolt and the internal gear.

5. The adjustable backlash less differential gear reducer of claim 1 wherein said external gear is connected to the input crank by a first angular contact ball bearing.

6. The adjustable-clearance small-tooth-difference speed reducer according to claim 5, wherein the external gear is fixed on the first angular contact ball bearing through a thermal expansion method, and the first angular contact ball bearing is fixed on the input crank through an interference fit and a shaft shoulder, and is used for offsetting the axial force generated by the clearance adjusting module.

7. The reducer of claim 1, wherein a step for fixing and separating two pieces of said inner gears is provided in said transmission housing; an elastic gasket is arranged between the step and the inner gear, and the rigidity of the elastic gasket is smaller than that of the gap adjusting module.

8. The adjustable backlash reducer with small tooth difference according to claim 1, wherein the thin end of the tooth thickness of said internal gear is in contact engagement with the thick end of the tooth thickness of said external gear.

9. The adjustable gap small tooth difference speed reducer of claim 1, wherein the pin supports are connected by a second deep groove ball bearing.

10. The adjustable gap reduction gear with small tooth difference as claimed in claim 1, characterized in that the pin shaft brackets are symmetrically arranged in two in the transmission housing, wherein the pin shaft bracket facing the power input end of the input crank is arranged on the transmission housing by a second angular contact ball bearing, and the other pin shaft bracket is arranged on the transmission housing by a first deep groove ball bearing.