WO2022110449A1

WO2022110449A1 - 3d printer and belt tensioning apparatus thereof

Info

Publication number: WO2022110449A1
Application number: PCT/CN2020/139841
Authority: WO
Inventors: 刘辉林; 唐京科; 陈春; 敖丹军; 皮小园
Original assignee: 深圳市创想三维科技有限公司
Priority date: 2020-11-30
Filing date: 2020-12-28
Publication date: 2022-06-02
Also published as: CN214111495U

Abstract

The present application provides a 3D printer and a belt tensioning apparatus thereof. The belt tensioning apparatus comprises a first synchronous wheel, a second synchronous wheel, a synchronous belt, a first adjustment block, a second adjustment block, and an adjustment member. The first synchronous wheel and the second synchronous wheel are connected by means of the synchronous belt, and the synchronous belt is an open-type toothed synchronous belt. The first adjustment block is connected to one open end of the synchronous belt, and is provided with a first adjustment hole. The second adjustment block is connected to the other open end of the synchronous belt, and is provided with a second adjustment hole. The adjustment member is connected to the first adjustment hole and the second adjustment hole for driving the first adjustment block and the second adjustment block to move toward each other or move back to back. According to the present application, the tensioning degree of the synchronous belt can be conveniently adjusted.

Description

3D printer and its belt tensioner

technical field

The present application relates to the field of 3D printing, and in particular, to a 3D printer and a belt tensioning device thereof.

Background technique

Three-dimensional (Three Dimensions, 3D) printing is rapid prototyping technology, is a cumulative manufacturing technology, also known as additive manufacturing, it is a digital model file-based, using special wax, powdered metal or plastic can be bonded materials, which create three-dimensional objects by printing layers of adhesive material. Fused deposition rapid prototyping (FDM), also known as hot melt deposition technology, is one of the main 3D printing technologies. The technology is to heat and melt the hot-melt filament, extrude it from the nozzle, and deposit it on the printing work platform or the previous layer of cured material. When the temperature is lower than the curing temperature of the filament, it starts to solidify and form, and finally print into a solid.

The structural forms of 3D printers currently on the market include Cartesian space coordinate form, COREXY structural form and DELTA structural form. In the Cartesian space coordinate form, if the printing size is large, two belts are usually used in one direction, and the tension of the two belts may be inconsistent, and the belt tension adjustment of the existing 3D printers It is also inconvenient, and the tension of the belt will directly affect the printing quality of the 3D printing model. How to solve the above problems is what those skilled in the art need to consider.

Utility model content

In view of this, in order to solve at least one of the technical problems existing in the prior art, one aspect of the present application is to provide a 3D printer and a belt tensioning device thereof, which can conveniently adjust the tensioning degree of the synchronous belt.

An embodiment of the present application provides a belt tensioning device for a 3D printer, including a first synchronous wheel, a second synchronous wheel, a synchronous belt, a first adjustment block, a second adjustment block, and an adjustment member. The first synchronous wheel and the second synchronous wheel are connected through the synchronous belt, and the synchronous belt is an open toothed synchronous belt. The first adjusting block is connected with an open end of the synchronous belt, and the first adjusting block is provided with a first adjusting hole. The second adjusting block is connected with the other open end of the synchronous belt, and the second adjusting block is provided with a second adjusting hole. The adjusting member is connected with the first adjusting hole and the second adjusting hole, and is used for driving the first adjusting block and the second adjusting block to move toward each other, or to move opposite to each other.

In a possible implementation manner, the first adjustment block is further provided with a first positioning hole, the second adjustment block is further provided with a second positioning hole, and the belt tensioning device further includes a fixing block, a first positioning hole A locking piece and a second locking piece. The fixing block is provided with a third positioning hole and a fourth positioning hole. The first locking piece passes through the first positioning hole and is partially received in the third positioning hole, so as to fix the first adjusting block on the fixing block. The second locking member passes through the second positioning hole and is partially received in the fourth positioning hole, so as to fix the second adjusting block on the fixing block.

In a possible implementation manner, the fixing block is provided with a guide groove, and the first adjusting block and the second adjusting block are detachably embedded in the guide groove.

In a possible implementation manner, the guide groove is recessed on one side of the fixing block, and the width of the guide groove is not smaller than the width of the first adjusting block and the width of the second adjusting block.

In a possible implementation manner, the first locking member and the second locking member are both countersunk screws, and the first positioning hole and the second positioning hole are both elliptical-like in shape, so The length of the long axis of the first positioning hole is greater than the length of the head of the countersunk screw.

In a possible implementation manner, the belt tensioning device further includes a first buckle and a second buckle respectively connected with the two open ends of the synchronous belt, and the first adjustment block includes a a body and a first vertical part, the first adjustment hole is provided on the first vertical part, the first body is provided with a first engaging part, and the first adjustment block passes through the first The engaging portion and the first engaging piece are engaged with an open end of the synchronous belt, the second adjusting block includes a second body and a second vertical portion, and the second adjusting hole is arranged in the On the second vertical portion, the second body is provided with a second engaging portion, and the second adjusting block passes through the second engaging portion and the second engaging piece and the other side of the synchronous belt. Open end snaps.

In a possible implementation, the belt tensioning device further includes a first rotating optical axis, a second rotating optical axis and a plurality of screws, and the first synchronizing wheel is rotatably sleeved on the first rotating shaft an optical axis, the second synchronizing wheel is rotatably sleeved on the second rotating optical axis, and the first synchronizing wheel is provided with a first threaded hole, so that the screw can be matched with the first threaded hole The first synchronizing wheel is locked on the first rotating optical axis, and the second synchronizing wheel is provided with a second threaded hole, so that the screw can cooperate with the second threaded hole to assemble the second threaded hole. The synchronizing wheel is locked on the second rotating optical axis.

In a possible implementation, the first synchronizing wheel includes a first annular portion, a second annular portion, and a first wheel groove located between the first annular portion and the second annular portion, and the The second synchronizing wheel includes a third annular portion, a fourth annular portion and a second wheel groove located between the third annular portion and the fourth annular portion, the first wheel groove and the second wheel groove Set in conjunction with the timing belt.

In a possible implementation manner, the width of the first annular portion is greater than the width of the second annular portion, the first threaded hole is provided on the first annular portion, and the third annular portion has a width The width is greater than the width of the fourth annular portion, the second threaded hole is arranged on the third annular portion, the first threaded hole and the second threaded hole are both composed of a threaded inner wall and a smooth inner wall, so The diameter of the threaded inner wall is smaller than the diameter of the smooth inner wall.

An embodiment of the present application further provides a 3D printer, including the aforementioned belt tensioning device.

Compared with the prior art, the 3D printer and its belt tensioning device of the present application can conveniently adjust the tensioning degree of the synchronous belt, and it is convenient to adjust the tensioning degree of the two synchronous belts to be consistent, so as to avoid the printing process. The inconsistent tension of the two timing belts will affect the print quality.

Description of drawings

FIG. 1 is a schematic structural diagram of a belt tensioning device in an embodiment.

FIG. 2 is a schematic structural diagram of the belt tensioning device shown in FIG. 1 to realize the tension adjustment part of the synchronous belt.

FIG. 3 is a schematic structural diagram of the first synchronizing pulley and the second synchronizing pulley of the feed belt tensioning device shown in FIG. 2 .

FIG. 4 is a schematic structural diagram of a belt tensioning device in another embodiment.

FIG. 5 is a schematic structural diagram of a 3D printer in an embodiment.

Description of main component symbols

Belt tensioner 100

3D printer 200

The first rotating optical axis 10

The second rotating optical axis 11

The first synchronizing wheel 12

Second synchronizing wheel 13

Timing belt 14

The first adjustment block 15

The second adjustment block 16

Adjustment piece 17

Fixed block 18

The first locking piece 19

The second locking piece 20

The first card fastener 21

The second card fastener 22

The first threaded hole 121

The first annular part 122

Second Ring Section 123

1st round slot 124

The second threaded hole 131

Third Ring Section 132

Fourth Ring Section 133

2nd round slot 134

Open

end

141, 142

first vertical section 151

The first ontology 152

Second vertical section 161

Second ontology 162

Guide groove 181

The third positioning hole 182

Fourth positioning hole 183

screw 1211

The first adjustment hole 1511

The first positioning hole 1521

The first engaging part 1522

The second adjustment hole 1611

The second positioning hole 1621

The second engaging part 1622

The first sub guide groove 1811

The second sub guide groove 1812

The third sub guide groove 1813

Detailed ways

The following description will refer to the accompanying drawings to more fully describe the content of the present application. Exemplary embodiments of the present application are shown in the drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. These exemplary embodiments are provided so that this application will be thorough and complete, and will fully convey the scope of this application to those skilled in the art. Like reference numbers refer to the same or similar components.

It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. When an element is referred to as being "disposed on" another element, it can be directly disposed on the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and similar expressions are used herein for illustrative purposes only.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used herein in the specification of the present application are for the purpose of describing particular embodiments only, and are not intended to limit the present application. As used herein, the term "or/and" includes any and all combinations of one or more of the associated listed items.

Exemplary embodiments will be described below with reference to the accompanying drawings. It should be noted that the components depicted in the reference figures are not necessarily shown to scale; rather, the same or similar components will be given the same or similar reference numerals or similar technical terms.

The present application provides a belt tensioning device for a 3D printer, which includes a first synchronizing wheel, a second synchronizing wheel, a synchronous belt, a first adjusting block, a second adjusting block and an adjusting member. The first synchronous wheel and the second synchronous wheel are connected through the synchronous belt, and the synchronous belt is an open toothed synchronous belt. The first adjustment block is connected with an open end of the synchronous belt, and the first adjustment block is provided with a first adjustment hole. The second adjusting block is connected with the other open end of the synchronous belt, and the second adjusting block is provided with a second adjusting hole. The adjusting member is connected with the first adjusting hole and the second adjusting hole, and is used for driving the first adjusting block and the second adjusting block to move toward each other, or to move opposite to each other.

The belt tensioning device of the above-mentioned 3D printer drives the first adjustment block and the second adjustment block to move toward each other by twisting the adjustment piece, or to move opposite to each other, thereby tightening or loosening the synchronous belt.

Some embodiments of the present application are described in detail. The following embodiments and features of the embodiments may be combined with each other without conflict.

Referring to FIG. 1 and FIG. 2 , an embodiment of the present application provides a belt tensioning device 100 for a 3D printer. The belt tensioning device 100 is installed in the 3D printer. The belt tensioning device 100 includes a first rotating optical axis 10, a second rotating optical axis 11, a first synchronizing pulley 12, a second synchronizing pulley 13, a synchronizing belt 14, a first adjusting block 15, a second adjusting block 16, and an adjusting member 17. Fixed block 18, first locking member 19, second locking member 20. The first synchronizing wheel 12 is rotatably sleeved on the first rotating optical shaft 10 , and the second synchronizing wheel 13 is rotatably sleeved on the second rotating optical shaft 11 . The first synchronous wheel 12 and the second synchronous wheel 13 are connected by a synchronous belt 14, and the synchronous belt 14 can be optionally an open toothed synchronous belt. The first adjusting block 15 is connected to an open end 141 of the timing belt 14 , and the first adjusting block 15 is provided with a first adjusting hole 1511 . The second adjusting block 16 is connected to the other open end 142 of the timing belt 14 , and the second adjusting block 16 is provided with a second adjusting hole 1611 . The adjusting member 17 is connected with the first adjusting hole 1511 and the second adjusting hole 1611, and by twisting the adjusting member 17, the first adjusting block 15 and the second adjusting block 16 can be driven to move toward each other, or to move opposite to each other, thereby realizing locking or loosening. Timing belt 14. For example, when the adjusting member 17 is rotated to drive the first adjusting block 15 and the second adjusting block 16 to move toward each other, the synchronous belt 14 is locked. When the back is moving, the synchronous belt 14 is loosened. The fixing block 18 is provided with a guide groove 181 , and the first adjusting block 15 and the second adjusting block 16 are detachably embedded in the guide groove 181 and can slide in the guide groove 181 .

The first locking member 19 can fix the first adjusting block 15 on the fixing block 18 , and the second locking member 20 can fix the second adjusting block 16 on the fixing block 18 . When the first locking member 19 is tightened, the first adjusting block 15 cannot slide in the guide groove 181 , and when the first locking member 19 is loosened, the first adjusting block 15 can slide in the guide groove 181 . When the second locking member 20 is tightened, the second adjusting block 16 cannot slide in the guide groove 181 , and when the second locking member 20 is loosened, the second adjusting block 16 can slide in the guide groove 181 .

In some embodiments, a guide groove 181 is formed concavely on one side of the fixing block 18, and the width of the guide groove 181 can be selected to be no less than the width of the first adjustment block 15 and the width of the second adjustment block 16, so that the first adjustment block 15. The second adjusting block 16 can slide in the guide groove 181 .

Please refer to FIG. 3 , the first synchronizing wheel 12 and the second synchronizing wheel 13 have the same structure. The first synchronizing wheel 12 is provided with first threaded holes 121, and the number of the first threaded holes 121 can be set according to actual needs. For example, the first synchronizing wheel 12 is provided with two first threaded holes 121 . The screw 1211 is matched with the first threaded hole 121 (threaded connection) to realize the locking of the first synchronizing wheel 12 to the first rotating optical axis 10 .

For example, when the screw 1211 is rotated clockwise until the bottom end of the screw 1211 is pressed against the first rotating optical axis 10, the first synchronizing wheel 12 can be locked on the first rotating optical axis 10. At this time, the first synchronizing wheel 12 cannot be Rotate relative to the first rotating optical axis 10 . When the screw 1211 is rotated counterclockwise until the bottom end of the screw 1211 is out of contact with the first rotating optical axis 10 , the first synchronizing wheel 12 can rotate relative to the first rotating optical axis 10 at this time.

Likewise, the second synchronizing wheel 13 is provided with second threaded holes 131 , and the number of the second threaded holes 131 can be set according to actual requirements. The screw 1211 is threadedly connected with the second threaded hole 131. When the screw 1211 is rotated clockwise until the bottom end of the screw 1211 is pressed against the second rotating optical axis 11, the second synchronizing wheel 13 can be locked on the second rotating optical axis 11. , at this time, the second synchronizing wheel 13 cannot rotate relative to the second rotating optical axis 11 . When the screw 1211 is rotated counterclockwise until the bottom end of the screw 1211 is out of contact with the second rotating optical axis 11 , the second synchronizing wheel 13 can rotate relative to the second rotating optical axis 11 .

In some embodiments, screws 1211 include, but are not limited to, machine screws.

The first synchronizing wheel 12 includes a first annular portion 122 , a second annular portion 123 and a first wheel groove 124 . The first wheel groove 124 is located between the first annular portion 122 and the second annular portion 123 . The width of the first annular portion 122 can be optionally larger than the width of the second annular portion 123 , and the first threaded hole 121 is disposed on the first annular portion 122 . The second synchronizing wheel 13 includes a third annular portion 132 , a fourth annular portion 133 and a second wheel groove 134 . The second wheel groove 134 is located between the third annular portion 132 and the fourth annular portion 133 . The width of the third annular portion 132 is greater than the width of the fourth annular portion 133 , and the second threaded hole 131 is disposed on the third annular portion 132 . The timing belt 14 is arranged in cooperation with the first wheel groove 124 and the second wheel groove 134 , so that the timing belt 14 can slide in the first wheel groove 124 and the second wheel groove 134 .

The structures of the first threaded hole 121 and the second threaded hole 131 are the same. The first threaded hole 121 can be optionally composed of two parts: a threaded inner wall and a smooth inner wall. The diameter of the threaded inner wall can be selected to be smaller than the diameter of the smooth inner wall, so that the head of the screw 1211 can be accommodated in the smooth inner wall, so that the screw 1211 can be hidden and installed in the first threaded hole. A synchronizing wheel 12 and a second synchronizing wheel 13 .

Referring to FIG. 4 , the belt tensioning device 100 further includes a first fastener 21 and a second fastener 22 . The first adjusting block 15 includes a first vertical portion 151 and a first body 152 . The first adjusting hole 1511 is disposed on the first vertical portion 151 , and the first body 152 is further provided with a first positioning hole 1521 and a first engaging portion 1522 . The second adjusting block 16 includes a second vertical portion 161 and a second body 162 . The second adjusting hole 1611 is provided on the second vertical portion 161 , and the second body 162 is further provided with a second positioning hole 1621 and a second engaging portion 1622 . The fixing block 18 includes a third positioning hole 182 and a fourth positioning hole 183 . The first locking member 19 can pass through the first positioning hole 1521 and be partially accommodated in the third positioning hole 182, so that the first adjusting block 15 can be fixed on the fixing block 18; the second locking member 20 can pass through the second positioning hole 182. The hole 1621 is partially accommodated in the fourth positioning hole 183 , so that the second adjusting block 16 can be fixed on the fixing block 18 .

Specifically, when the first locking member 19 is rotated to lock and fix the first adjusting block 15 on the fixing block 18, the first adjusting block 15 will not be able to slide in the guide groove 181. The second adjusting block 16 is locked and fixed on the fixing block 18 , and the second adjusting block 16 cannot slide in the guide groove 181 . When the timing belt 14 needs to be tensioned and adjusted, the first locking member 19 and the second locking member 20 need to be released, so that the first adjusting block 15 and the second adjusting block 16 can slide in the guide groove 181 .

In some embodiments, the first engaging portion 1522 and the second engaging portion 1622 include, but are not limited to, a U-shaped shape, and the first adjusting block 15 can be connected to the timing belt through the first engaging portion 1522 and the first engaging member 21 . The open end 141 of 14 is snapped. The second adjusting block 16 can be engaged with the open end 142 of the timing belt 14 through the second engaging portion 1622 and the second engaging member 22 .

Specifically, the open end 141 of the timing belt 14 protrudes from one surface of the first engaging portion 1522 and protrudes from the other surface of the first engaging portion 1522 . The connection is made so that the open end 141 will not be disengaged from the first engaging portion 1522 , so that the opening end 141 and the first engaging portion 1522 are engaged with each other. The open end 142 of the timing belt 14 protrudes from one surface of the second engaging portion 1622 and protrudes from the other surface of the second engaging portion 1622, and the protruding portion of the open end 142 is connected to the second engaging member 22, so that the The open end 142 will not be disengaged from the second engaging portion 1622 , so that the opening end 142 is engaged with the second engaging portion 1622 .

In some embodiments, the guide groove 181 includes a first sub-guide groove 1811 , a second sub-guide groove 1812 and a third sub-guide groove 1813 . The second sub-guide groove 1812 is located between the first sub-guide groove 1811 and the third sub-guide groove 1813. The depths of the first sub-guide groove 1811 and the third sub-guide groove 1813 are the same, and the depth of the second sub-guide groove 1812 is smaller than that of the third sub-guide groove 1812. The depth of a sub-guide groove 1811 is convenient for the open ends 141 and 142 of the timing belt 14 to respectively protrude from one surface of the engaging

parts

1522 and 1622 and protrude from the other surface. The first adjusting block 15 and the second adjusting block 16 can slide in the second sub-guide groove 1812 .

In some embodiments, the first locking member 19 and the second locking member 20 include but are not limited to countersunk head screws, the adjusting member 17 may include bolts and nuts, or only bolts, and the bolts may be with a hand wheel or without Handwheel bolts. The first positioning hole 1521 and the second positioning hole 1621 can be optionally both elliptical-like in shape, and the length of the long axis of the first positioning hole 1521 is greater than the diameter of the third positioning hole 182, so that when adjusting the tension of the synchronous belt 14, the A positioning hole 1521 and the third positioning hole 182 can be kept through. The length of the long axis of the second positioning hole 1621 is greater than the diameter of the fourth positioning hole 183 , so that when the tension of the timing belt 14 is adjusted, the second positioning hole 1621 and the fourth positioning hole 183 can remain connected.

Referring to FIG. 5 , an embodiment of the present application further provides a 3D printer 200 . The 3D printer 200 includes two belt tensioning devices 100 in the above embodiment, and the two belt tensioning devices 100 share the first rotating optical axis 10 and the The second rotating optical axis 11 . The tension adjustment of the two synchronous belts 14 of the 3D printer 200 can be performed in the following ways, so that the tension of the two synchronous belts 14 tends to be consistent, so as to improve the 3D printing quality: a. For a belt tensioning device 100, loosen the first A synchronizing wheel 12 and a screw 1211 of the second synchronizing wheel 13; b. Loosen the first locking member 19 and the second locking member 20; c. The tension of the belt 14, if the test force is the same as the specified force, stop rotating the adjusting member 17, and lock the first locking member 19 and the second locking member 20; d. Lock the first synchronizing wheel 12 and the The screw 1211 of the second synchronizing wheel 13; e. Repeat the above steps a-d to adjust the other belt tensioning device 100.

Hereinabove, specific embodiments of the present application have been described with reference to the accompanying drawings. However, those skilled in the art can understand that various changes and substitutions can be made to the specific embodiments of the present application without departing from the spirit and scope of the present application. These changes and substitutions fall within the scope defined by this application.

Claims

A belt tensioning device for a 3D printer, comprising a first synchronous wheel, a second synchronous wheel and a synchronous belt, the first synchronous wheel and the second synchronous wheel are connected by the synchronous belt, and the synchronous belt is an opening type toothed synchronous belt with two open ends, characterized in that, the belt tensioning device further includes:

a first adjustment block, connected with an open end of the synchronous belt, the first adjustment block is provided with a first adjustment hole;

a second adjusting block, connected to the other open end of the synchronous belt, the second adjusting block is provided with a second adjusting hole;

The adjusting member is connected with the first adjusting hole and the second adjusting hole, and is used for driving the first adjusting block and the second adjusting block to move toward each other, or to move opposite to each other.
The belt tensioning device according to claim 1, wherein the first adjusting block is further provided with a first positioning hole, the second adjusting block is further provided with a second positioning hole, and the belt tensioning device is further provided with a first positioning hole. Also includes:

The fixing block is provided with a third positioning hole and a fourth positioning hole;

a first locking member, which passes through the first positioning hole and is partially accommodated in the third positioning hole, so as to fix the first adjusting block on the fixing block;

The second locking member passes through the second positioning hole and is partially accommodated in the fourth positioning hole, so as to fix the second adjusting block on the fixing block.
The belt tensioning device according to claim 2, wherein the fixing block is provided with a guide groove, and the first adjusting block and the second adjusting block are detachably embedded in the guide groove.
The belt tensioning device according to claim 3, wherein the guide groove is recessed on one side of the fixing block, and the width of the guide groove is not less than the width of the first adjusting block and the width of the first adjusting block. The width of the second adjustment block.
The belt tensioning device according to claim 2, wherein the first locking member and the second locking member are both countersunk screws, and the first positioning hole and the second positioning hole are Both are oval-like shapes, the length of the major axis of the first positioning hole is greater than the diameter of the third positioning hole, and the length of the major axis of the second positioning hole is greater than the diameter of the fourth positioning hole.
The belt tensioning device according to claim 1, characterized in that, the belt tensioning device further comprises a first buckle piece and a second buckle piece respectively connected with the two open ends of the synchronous belt. The first adjustment block includes a first body and a first vertical portion, the first adjustment hole is provided on the first vertical portion, the first body is provided with a first engaging portion, the first The adjusting block is clamped with an open end of the synchronous belt through the first engaging part and the first latching piece, the second adjusting block includes a second body and a second vertical part, the first Two adjustment holes are provided on the second vertical portion, the second body is provided with a second engaging portion, and the second adjusting block is connected to the second engaging portion and the second engaging piece through the second engaging portion and the second engaging piece. The other open end of the synchronous belt is clamped.
The belt tensioning device according to claim 1, wherein the belt tensioning device further comprises a first rotating optical axis, a second rotating optical axis and a plurality of screws, and the first synchronizing wheel is rotatably sleeved Set on the first rotating optical axis, the second synchronizing wheel is rotatably sleeved on the second rotating optical axis, and the first synchronizing wheel is provided with a first threaded hole, so that the screw can be connected with the screw. The first threaded hole cooperates to lock the first synchronizing wheel to the first rotating optical axis, and the second synchronizing wheel is provided with a second threaded hole, so that the screw can be connected with the second thread The holes cooperate to lock the second synchronizing wheel to the second rotating optical axis.
8. The belt tensioning device of claim 7, wherein the first synchronizing pulley comprises a first annular portion, a second annular portion, and a second annular portion located between the first annular portion and the second annular portion a first wheel groove, the second synchronizing wheel includes a third annular portion, a fourth annular portion and a second wheel groove located between the third annular portion and the fourth annular portion, the first wheel groove and the second wheel groove is matched with the synchronous belt.
The belt tensioning device according to claim 8, wherein the width of the first annular portion is greater than the width of the second annular portion, and the first threaded hole is provided on the first annular portion, The width of the third annular portion is greater than the width of the fourth annular portion, the second threaded hole is arranged on the third annular portion, and the first threaded hole and the second threaded hole are both threaded The inner wall and the smooth inner wall are formed, and the diameter of the inner wall of the thread is smaller than the diameter of the smooth inner wall.
A 3D printer is characterized by comprising the belt tensioning device according to any one of claims 1-9.