Counter-rotating differential speed extrusion device, extruder and method for manufacturing materials

Patent metadata

Field	Value
Publication number	US-11485063-B2
Application number	US-202017007886-A
Country	US
Kind code	B2
Filing date	Aug 31, 2020
Priority date	Mar 25, 2020
Publication date	Nov 1, 2022
Grant date	Nov 1, 2022

Abstract

A counter-rotating differential speed extrusion device includes a barrel and a screw mechanism in the barrel comprising a first and second screws. A crest diameter and a root diameter of the first screw are respectively meshed with that of the second screw; the first and second screws counter-rotate in differential speeds at a fixed rotation speed ratio; at least one first intermediate circular arc structure with a trend consistent with that of the crest diameter and the root diameter of the first screw is provided between the root diameter and the crest diameter of the first screw, a second intermediate circular arc structure tangent to the first intermediate circular arc structure and having a trend consistent with that of the root diameter and the crest diameter of the second screw is provided between the root diameter and the crest diameter of the second screw.

First claim

We claim:

1. A counter-rotating differential speed extrusion device, comprising a barrel and a screw mechanism arranged in the barrel, the screw mechanism comprising a first screw and a second screw,
wherein a crest diameter and a root diameter of the first screw are respectively meshed with a root diameter and a crest diameter of the second screw; the first screw and the second screw are configured for counter-rotating in differential speeds at a fixed rotation speed ratio;
at least one first intermediate circular arc structure is provided between the root diameter and the crest diameter of the first screw, a second intermediate circular arc structure that is tangent to the first intermediate circular arc structure is provided between the root diameter and the crest diameter of the second screw;
a trend of the first intermediate circular arc structure is consistent with a thread trend of the crest diameter and the root diameter of the first screw;
a trend of the second intermediate circular arc structure is consistent with a thread trend of the root diameter and the crest diameter of the second screw;
wherein the first intermediate circular arc structure is disposed on one side or both sides of the crest diameter of the first screw, and the second intermediate circular arc structure is also disposed on one side or both sides of the crest diameter of the second screw;
the first intermediate circular arc structure and the second intermediate circular arc structure are jointly used to open a screw groove of the first screw and a screw groove of the second screw to each other, and form an “8”-shaped chamber positive displacement conveying unit.

2. The counter-rotating differential speed extrusion device of claim 1 , wherein a rotation speed of the first screw is N 1 , a rotation speed of the second screw is N 2 , and N 1 and N 2 are positive integers that are relatively prime;
in each cross section of the screw mechanism, a cross-sectional profile of the first screw and a cross-sectional profile of the second screw comprise multiple continuous curved arcs,
and a number ratio of the curved arcs of the cross-sectional profile of the first screw and the curved arcs of the cross-sectional profile of the second screw is inversely proportional to the rotation speed ratio.

3. The counter-rotating differential speed extrusion device of claim 2 , wherein the first intermediate circular arc structure is provided on both sides of the crest diameter of the first screw,
the second intermediate circular arc structure is provided on both sides of the crest diameter of the second screw;
the cross-sectional profile of the first screw is composed of 8N 2 curved arcs;
the cross-sectional profile of the second screw is composed of 8N 1 curved arcs;
8N 2 curved arcs of the cross-sectional profile of the first screw comprises N 2 circular arcs AB, N 2 circular arcs EF, 2N 2 circular arcs CD, and 2N 2 non-circular arcs ED connecting circular arc EF and circular arc CD, 2N 2 non-circular arcs CB connecting circular arc CD and circular arc AB; diameters corresponding to AB, CD and EF are R, r M and r, C is a distance of a connecting line between a rotation center of the first screw and a rotation center of the second screw, and central angles corresponding to AB, CD and EF are α, β, and Y , respectively, parameters θ 1 ,θ 2 are given, then θ 1 ,θ 2 satisfy the following relational expressions:

∅
1

=

N
1

N
2

⁢
arccos
⁢

(

C
2

+

R
2

-

r
M
2

2
⁢
CR

)

-

acrsin
⁢

4
⁢

C
2

⁢

R
2

-

(

C
2

+

R
2

-

r
M
2

)

2

2
⁢

Cr
M

,

∅
2

=

N
1

N
2

⁢

arcos
(

(

C
+
R

)

⁢
r

+

(

C
-

r
M

Assignees

• Univ Wuyi

Inventors

• Xu Baiping
• Yu Huiwen
• Xiao Shuping
• Du Yaoxue

Classifications

• B29C48/59

  characterised by details of the thread, i.e. the shape of a single thread of the material-feeding screw · CPC title

• B29C48/41 Primary

  Intermeshing counter-rotating screws · CPC title

• B29C48/575

  provided with elements of a generally circular cross-section for shearing the melt, i.e. shear-ring elements · CPC title

• B29C48/425

  using three or more screws (serially arranged screws B29C48/38, B29C48/385) · CPC title

• B29C48/525

  Conical screws · CPC title