Nutation reducer

Patent metadata

Field	Value
Publication number	US-11933385-B2
Application number	US-202318241917-A
Country	US
Kind code	B2
Filing date	Sep 4, 2023
Priority date	Dec 22, 2021
Publication date	Mar 19, 2024
Grant date	Mar 19, 2024

Abstract

A nutation reducer includes: a case, two pairs of nutation gear pairs, each pair being disposed in the case and composed of a nutation gear and non-nutation gear in engagement, and the non-nutation gear being fixed in the case or integrated formed in the case; an output shaft, rotationally disposed in the case; two annular spring films, each nutation gear of the gear pair is connected to the output shaft through one annular spring film; a nutation generating mechanism disposed in the case, two nutation gear pairs being respectively disposed on both sides of the nutation generating mechanism. Power-split arrangement is applied in this application, symmetric layout of the nutation gear pairs is adopted. In this way, the working efficiency of the reducer is obviously improved, meanwhile the volume and weight of the reducer, and the heat generated in working process are reduced, and power density is improved.

First claim

The invention claimed is:

1. A nutation reducer, wherein the nutation reducer comprises:
a case;
two nutation gear pairs which are disposed in said case, wherein said nutation gear pair is composed of a nutation gear and a non-nutation gear in engagement, and said non-nutation gear is provided in said case in fixed manner or integrally formed with said case, a number of teeth of the nutation gear of said nutation gear pair being one more than that of said non-nutation gear;
an output shaft of the reducer which is rotationally provided in said case;
two pre-stretched annular spring films, which are respectively installed, on their respective sides, between the nutation gear and the output shaft of the reducer, to convert nutation movement of the nutation gear into single rotary movement of the output shaft of the reducer;
wherein the annular spring film is further designed to be able to bear a radial force of the nutation gear, so as to enable the annular spring film to have a function of a joint bearing and have a centering function for the nutation gear;
each of the annular spring films includes an inner ring, an outer ring, and an annular elastic portion connected to both the inner and outer rings;
the annular elastic portion is an annular bulge which is convex in one side and concave in the other side;
reamed holes are respectively distributed circumferentially in both inner and outer rings, and the nutation gear each is connected to the outer ring of said spring film by first hinged bolts which respectively pass through the reamed holes in said outer ring and fits with the reamed holes;
said output shaft is fixed to the inner ring of said spring film by second hinged bolts, and said second hinged bolts respectively pass through the reamed holds in said inner ring and fit with the reamed holes;
said inner ring is coaxially provided with said output shaft of the reducer, to which the inner ring is connected, and said outer rings are coaxially provided with said nutation gears, to which the outer ring is connected, each axis of the inner ring intersecting with that of the outer ring; and
a shaft angle between the nutation gear and the non-nutation gear is less than 180°, and the annular elastic portion is capable of compensating a pre-stretched deformation amount of a tensile deformation amount generated during installation of the annular spring film; and

a nutation generating mechanism disposed in said case, wherein the two nutation gear pairs are respectively arranged symmetrically on both sides of said nutation generating mechanism, and said nutation generating mechanism drives said nutation gears to perform the nutation movement, making the teeth of the nutation gear roll on the teeth of the non-nutation gear.

2. The nutation reducer as claimed in claim 1 , wherein said nutation generating mechanism comprises:
a tilted disc rotationally provided in said case on said output shaft, wherein two opposite sides of the tilted disc form a pair of symmetrically tilted planes, and said tilted disc is driven by an actuating mechanism; and
planar high-density ball bearings, wherein the planar high-density ball bearing is interposed between the tilted disc and the nutation gear of the nutation gear pairs, and both sides of the tilted disc and the back side of each nutation gear in said gear pairs serve as raceways of said planar high-density ball bearing;
wherein two nutation gears in two said nutation gear pairs have the same number of teeth, and the two non-nutation gears in two said nutation gear pairs have the same number of teeth, and
when said tilted disc rotates, the tilted planes on both sides of the tilted disc drives the nutation gears to perform the nutation movement, making the teeth of the nutation gears roll on the teeth of the non-nutation gears.

3. The nutation reducer as claimed in claim 2 , wherein the inner ring is tangent to an inner periphery of the annular elastic portion, while said outer ring is tangent to an outer periphery of the annular elastic portion.

4. The nutation reducer as claimed in claim 3 , wherein a concave and convex surfaces of said annular bulge are annular ripple bulge formed by circular arc camber, spline surface or cosine surface.

5. The nutation reducer as claimed in claim 2 , wherein an opening is formed in a side of said tilted disc where the tilted disc has a larger thickness to get dynamic balance when the tilted disc rotates.

6. The nutation reducer as claimed in claim 2 , wherein said driving mechanism is an electric motor, directly driving said tilted disc.

7. The nutation reducer as claimed in claim 6 , wherein said case serves as a case of said electric motor, in which a stator of said electric motor is embedded, and/or there is a neck contraction segment between the two tilted planes of said tilted disc, and said neck contraction segment serves as a rotor of said electric motor.

8. The nutation reducer as claimed in claim 2 , wherein said driving mechanism includes both an electric motor and a transmission mechanism, and said electric motor drives the tilted disc through said transmission mechanism.

9. The nutation reducer as claimed in claim 8 , wherein said transmission mechanism includes a transmission gear, and uniformly distributed gear teeth are made in a circumference of said tilted disc, wherein a gear is fixed to a shaft of the electric motor, and is in meshing engagement with the gear teeth in the tilted disc.

Assignees

• Jiang Hong

Inventors

• Wang Xiaochun

Classifications

• F16H1/321 Primary

  the orbital gear being nutating · CPC title

• F16H55/10

  Constructively simple tooth shapes, e.g. shaped as pins, as balls · CPC title

• F16H1/20 Primary

  involving more than two intermeshing members · CPC title

• F16H57/023

  Mounting or installation of gears or shafts in the gearboxes, e.g. methods or means for assembly · CPC title

• F16H57/021

  Shaft support structures, e.g. partition walls, bearing eyes, casing walls or covers with bearings · CPC title