CN106270798B

CN106270798B - The power drive mechanism of bellows groover

Info

Publication number: CN106270798B
Application number: CN201610794295.3A
Authority: CN
Inventors: 余风强; 王辉; 王俊洪
Original assignee: NINGBO FANGLI TECHNOLOGY Co Ltd
Current assignee: NINGBO FANGLI TECHNOLOGY Co Ltd
Priority date: 2016-08-31
Filing date: 2016-08-31
Publication date: 2019-09-27
Anticipated expiration: 2036-08-31
Also published as: CN106270798A

Abstract

The present invention provides the power drive mechanisms of bellows groover, belong to bellows processing technique field.It solves the problems, such as that the power drive mechanism transmission stability of existing bellows groover is poor.The power drive mechanism of this bellows groover includes: cabinet comprising two fixed plates；Main shaft, is set in two fixed plates and the both ends of main shaft are connected with two fixed plates respectively；Cutter shaft is set on main shaft and is connected with main shaft；Cutter is used for the fluting of bellows and is set to cutter shaft component；The main shaft energy band movable arbor rotates in same direction and circumferentially rotates cutter.The power drive mechanism of this bellows groover has the advantages that rationally distributed, stable drive.

Description

The power drive mechanism of bellows groover

Technical field

The invention belongs to bellows processing technique fields, are related to a kind of power drive mechanism, especially bellows groover Power drive mechanism.

Background technique

Bellows performance is good and with strong applicability, is widely used in more industry, for example, on bellows After aperture, bellows is embedded in below ground, water penetration can be flowed into bellows into soil by the hole on bellows, from And the problem of accelerating the speed that ponding is drained, effectively alleviating surface gathered water, and this bellows needs to add it It could be used after work fluting.

As mechanical automation development process is very fast, the fluting of bellows is completed also by fluting apparatus, when processing, wave It is mobile to fluting apparatus that line tube edge rotates side, while close to cutter, being carried out by the cutter rotation on fluting apparatus to bellows Fluting, when bellows remove fluting apparatus when, fluting terminates, and traditional fluting apparatus processing when there are following technologies to ask Topic: it in the fluting apparatus, is usually rotate in same direction by multiple cutters with bellows and is slotted to bellows, but existed in cutter Active force, which can be generated, to bellows in grooving process leads to the stable drive of bellows so that the position of bellows shifts Property is poor.

To solve groover in the prior art, there are the technical problems of transmission stability difference in bellows grooving process, need It designs a kind of for groover and rationally distributed, uniform force bellows power drive mechanism.

Summary of the invention

The purpose of the present invention is there is the above problem in view of the prior art, a kind of rationally distributed, stable drive is proposed The power drive mechanism of the high bellows groover of property.

Object of the invention can be realized by the following technical scheme: the power drive mechanism of bellows groover, comprising:

Cabinet comprising two fixed plates；

Main shaft, is set in two fixed plates and the both ends of main shaft are connected with two fixed plates respectively；

Cutter shaft is set on main shaft and is connected with main shaft；

Cutter is used for the fluting of bellows and is set to cutter shaft component；

The main shaft energy band movable arbor rotates in same direction and circumferentially rotates cutter.

In the power drive mechanism of above-mentioned bellows groover, main shaft is set as more and by synchronizing chain successively phase Even, around respectively between two fixed plates, the cutter shaft is set as more and corresponds with main shaft the more main shaft uniform rings, Drive chain is provided between main shaft and cutter shaft.

In the power drive mechanism of above-mentioned bellows groover, spindle bearing holder is provided on main shaft and in main shaft Be provided with main shaft linking arm on bearing block, offer card slot on main shaft linking arm, be provided on cutter shaft cutter shaft bearing block and It is provided with cutter shaft linking arm on cutter shaft bearing block, cutter shaft linking arm is provided with fixture block, the fixture block can be arranged in card slot.

In the power drive mechanism of above-mentioned bellows groover, tool apron, the cutter setting are provided on cutter shaft It is connected respectively with tool apron and cutter shaft in the both ends on tool apron, being provided with Synchronization Component and the Synchronization Component on tool apron, it is described Cutter shaft can be circumferentially rotated by tool apron band cutter and the Synchronization Component can make cutter and bellows synchronous shift.

In the power drive mechanism of above-mentioned bellows groover, the Synchronization Component includes elastic component and guide part, The elastic component is sheathed on main shaft and the both ends of elastic component are connected with tool apron and main shaft respectively, and the guide part is set to tool apron Excircle on, when the conveying speed of bellows fluctuates in a certain range, the guide part can make tool apron with bellows In the axial direction synchronizing moving and make tool apron drive elastic component compression or reset.

In the power drive mechanism of above-mentioned bellows groover, the guide part includes two being set to leading on tool apron To portion, mounting groove and the mounting groove are offered on tool apron between two guide parts, the cutter is set in mounting groove, The guiding arc that is connected with guide part is provided on the excircle of tool apron, the guiding arc is contacted with bellows with guide part.

In the power drive mechanism of above-mentioned bellows groover, the shape of the cross section of the cutter shaft is in polygon, Fixing groove corresponding with cutter shaft is offered on tool apron, the cutter shaft is arranged in fixing groove.

In the power drive mechanism of above-mentioned bellows groover, the main shaft includes the first main shaft and the second main shaft, More first main shafts are sequentially connected by the first synchronous chain, and second main shaft is sequentially connected by the second synchronous chain, Duo Gen One main shaft can rotate synchronously and with more rotate synchronously the rotation direction of the second main shaft it is opposite.

In the power drive mechanism of above-mentioned bellows groover, first main shaft and the second main shaft are successively spaced simultaneously It is uniformly distributed around in two fixed plates, being equidistant between the first main shaft and the second main shaft of arbitrary neighborhood.

In the power drive mechanism of above-mentioned bellows groover, several arc grooves are offered in two fixed plates, It is provided with tensioning wheel in each arc groove, the tensioning wheel is located at the first synchronous chain and the second synchronous chain side and described Chain synchronous with first and the second synchronous chain are connected tensioning wheel respectively.

Compared with prior art, the present invention includes cabinet, and main shaft and cutter shaft are provided on cabinet, is provided on cutter shaft For the cutter of bellows fluting, during present invention work, main shaft can be circumferentially rotated by cutter shaft band cutter, be guaranteed The stationarity that main shaft and cutter shaft are driven between the two, improves working efficiency of the invention.

Detailed description of the invention

Fig. 1 is structural schematic diagram of the invention.

Fig. 2 is cross-sectional view of the invention.

Fig. 3 is the structural schematic diagram that the present invention omits a fixed plate.

Fig. 4 is the structural schematic diagram of the first main shaft in a preferred embodiment of the present invention.

Fig. 5 is the structural schematic diagram of cutter shaft in a preferred embodiment of the present invention.

Fig. 6 is the structural schematic diagram of tool apron in a preferred embodiment of the present invention.

Fig. 7 is the cross-sectional view of tool apron in a preferred embodiment of the present invention.

Fig. 8 is the part-structure sectional view of tool apron in a preferred embodiment of the present invention.

Fig. 9 is the structural schematic diagram of the first cutter shaft cutter in a preferred embodiment of the present invention.

In figure, 100, fixed plate；200, the first main shaft；201, the first synchronous chain；202, the first spindle bearing holder；203, One main shaft linking arm；204, the first card slot；210, the first cutter shaft；211, the first cutter shaft bearing block；212, the first cutter shaft linking arm； 213, the first fixture block；220, the first drive chain；300, the second main shaft；301, the second synchronous chain；302, the second spindle bearing holder； 303, the second main shaft linking arm；304, the second card slot；310, the second cutter shaft；311, the second cutter shaft bearing block；312, the second cutter shaft Linking arm；313, the second fixture block；320, the second drive chain；400, sprocket wheel；401, bearing block；410, central spindle；420, tool apron；421, Guide part；422, mounting groove；423, fixation hole；424, fixing screws；425, it is oriented to arc；426, limit hole；427, stop screw； 500, cutter；510, cutter hub；520, blade；530, chip space；600, elastic component；700, cover board；800, tensioning wheel.

Specific embodiment

Following is a specific embodiment of the present invention in conjunction with the accompanying drawings, technical scheme of the present invention will be further described, However, the present invention is not limited to these examples.

As shown in Figures 1 to 9, the power drive mechanism of this bellows groover, comprising:

Cabinet comprising two fixed plates 100；

Main shaft, is set in two fixed plates 100 and the both ends of main shaft are connected with two fixed plates 100 respectively；

Cutter shaft is set on main shaft and is connected with main shaft；

Cutter 500 is used for the fluting of bellows and is set to cutter shaft component；

The spindle assemblies energy band moving knife shaft assembly rotates in same direction and circumferentially rotates cutter 500, makes cutter shaft by main shaft Band cutter 500 circumferentially rotates, and ensure that the stationarity that main shaft and cutter shaft are driven between the two, improves work effect of the invention Rate.

Above-mentioned main shaft is set as more and is sequentially connected by synchronous chain, and the more main shaft uniform rings are solid around being set to two Between fixed board 100, the cutter shaft is set as more and corresponds with main shaft, and drive chain is provided between main shaft and cutter shaft.

Power source is provided on cabinet, a main shaft in above-mentioned more main shafts is connected with power source, while in main shaft On be provided with synchronous chain, drive chain is provided between main shaft and cutter shaft, enables power source that main shaft is driven to rotate synchronously and lead to Chain belt of overdriving movable arbor rotates synchronously, and ensure that the synchronism rotated between each cutter shaft, avoids revolving speed occur between each cutter shaft Quality that is poor and influencing the fluting of cutter 500.

It is provided with spindle bearing holder on main shaft and is provided with main shaft linking arm on spindle bearing holder, in main shaft linking arm On offer card slot, cutter shaft bearing block 401 is provided on cutter shaft and is provided with cutter shaft linking arm on cutter shaft bearing block 401, Cutter shaft linking arm is provided with fixture block, the fixture block can be arranged in card slot, ensure that the firm of both cutter shaft and main shaft connection Property, it ensure that normal work of the invention.

Tool apron 420 is provided on cutter shaft, the cutter 500 is set on tool apron 420, is provided on tool apron 420 same The both ends of step component and the Synchronization Component are connected with tool apron 420 and cutter shaft respectively, and the cutter shaft can be by tool apron 420 with moving knife Tool 500 circumferentially rotates and the Synchronization Component can make cutter 500 and bellows synchronous shift.

Above-mentioned Synchronization Component includes elastic component 600, and elastic component 600 is sheathed on cutter shaft and the both ends of elastic component 600 are distinguished It is connected with tool apron 420 and cutter shaft, above-mentioned cutter shaft energy band moving knife seat 420 circumferentially rotates and tool apron 420 can be made axially to move on cutter shaft Dynamic, when the conveying speed of bellows changes in a certain range, 420 energy band cutter 500 of tool apron is along cutter shaft in axis It is shifted up to side and compresses elastic component 600, ensure that cutter 500 can be with bellows synchronizing moving, so that cutter 500 is being opened Each face trough, ensure that the fluting quality of bellows during slot.

Above-mentioned elastic component 600 is preferably spring, but the elastic component 600 is not limited to spring, can have for other The component of elasticity.

It is provided with the sprocket wheel 400 being connected with main shaft in one end of cutter shaft, ensure that both sprocket wheel 400 and main shafts power transmits Stability, the other end of cutter shaft is provided with dismountable cover board 700, one end of above-mentioned spring is resisted against on cover board 700, bullet The other end of spring is resisted against on tool apron 420, facilitates the disassembly of spring.

Bearing block 401 is provided on cutter shaft, bearing block 401 is between sprocket wheel 400 and tool apron 420, in bearing block 401 It is additionally provided with central spindle 410 between tool apron 420, the more limit holes 426 for running through tool apron 420 are offered on tool apron 420, are being limited Stop screw 427 is provided in the hole 426 of position, one end of stop screw 427 passes through limit hole 426 and is threadedly connected to central spindle 410 On, to ensure that the stability of both central spindle 410 and tool apron 420 connection, cutter shaft is enabled to drive tool apron by central spindle 410 420 circumferentially rotate, and ensure that cutter shaft passes through the stability that tool apron 420 is driven with cutter 500.

The cross sectional shape of above-mentioned cutter shaft is in polygon, and fixing groove corresponding with polygon, cutter shaft are offered in central spindle 410 It is sheathed in fixing groove, so that 410 energy band moving knife seat 420 of central spindle is along cutter shaft axial movement, tool apron 420 can be with simultaneously Cutter shaft, which synchronizes, to be circumferentially rotated, and the conveying speed for making to obtain bellows is when a certain range changes, 410 energy band moving knife seat 420 of central spindle Synchronous variation occurs for displacement in the axial direction, guarantees necking tool each face trough in grooving process, ensure that bellows The planarization of notch.

Preferably, above-mentioned Synchronization Component further includes multiple groups guide part and guide part is set on the excircle of tool apron 420, respectively Group guidance set include two guide parts 421 being arranged in parallel on tool apron 420, offered on tool apron 420 mounting groove 422 and Between two guide parts 421, the cutter 500 is set in mounting groove 422 mounting groove 422, when tool apron 420 is set to When on bellows, above-mentioned guide part 421 can be protruded into the trough of bellows.

Two guide parts 421 are respectively arranged in two trough of bellows, when the conveying speed of bellows is sent out in a certain range When changing, tool apron 420 can under the action of two guide part 421 with bellows synchronizing moving in the axial direction, and cutter 500 It is set to the integral multiple that the spacing between two guide parts 421 and between necking tool and guide part 421 is bellows wavelength, to protect The equal face trough of incision site for demonstrate,proving cutter 500, improves the fluting quality of necking tool.

Further, also spiral is provided with guiding arc 425 and guiding arc 425 by cutter 500 on the excircle of tool apron 420 End extends on guide part 421, and the length of guiding arc 425 is greater than or equal to the perimeter between connected two troughs of bellows, from And during bellows axial movement, guiding arc 425 can be arranged on bellows, so that tool apron 420 and bellows are in axis To on direction when synchronizing moving, during ensure that tool apron 420 is circumferentially rotated with cutter 500, the incision site of cutter 500 It is respectively positioned in trough, improves the fluting quality of bellows.

The fixation hole 423 for communicating and being obliquely installed with mounting groove 422 is offered in tool apron 420, above-mentioned 500 one end of cutter is inserted When in mounting groove 422, one end that fixing screws 424 and fixing screws 424 are provided in fixation hole 423 can pass through fixation Hole 423 is simultaneously resisted against on cutter 500, ensure that the stability that cutter 500 is installed, and avoids cutter during present invention work 500 appearance positions deviate and influence the generation of bellows notch planarization phenomenon, improve working efficiency of the invention.

Above-mentioned cutter 500 includes cutter hub 510, and it is in flat blade 520 that cutter hub 510, which upwardly extends and is formed with shape, Cutting face is provided on middle blade 520 and offers the chip space 530 that shape is in crescent on cutting face, is worked in the present invention In the process, chip caused by 520 raised grain pipe of blade can be skidded off along chip space 530, and chip is avoided to be retained in bellows Surface and the normal work for influencing blade 520, improve working efficiency of the invention.

The present invention on the basis of the said structure, is further improved it.

Above-mentioned main shaft can be divided into more first main shafts 200 and the second main shaft of Duo Gen 300, cutter shaft can respectively with the first main shaft 200 corresponding first cutter shafts 210 and second cutter shaft 310 corresponding with the second main shaft 300, in the first main shaft 200 and the first cutter shaft It is provided with the first drive chain 220 between 210, the second drive chain 320 is provided between the second main shaft 300 and the second cutter shaft 310.

Preferably, above-mentioned first main shaft 200 is provided with 3, and the first synchronous chain is arranged on 3 first main shafts 200 201,3 first main shafts 200 are rotated synchronously.

Above-mentioned second main shaft 300 is set as more and is sequentially connected, it is preferable that the quantity of second main shaft 300 and first The corresponding quantity of main shaft 200 is 3, and the second synchronous chain 301 is arranged on 3 second main shafts 300.

The setting of above-mentioned first synchronous chain 201 chain 301 synchronous with second is so that 3 first main shafts 200 are connected and 3 second Main shaft 300 is connected, while the first synchronous chain 201 and the second synchronous chain 301 are connected with the same power source, so that above-mentioned 3 pieces the One the second main shaft of main shaft 200 and 3 piece 300 can rotate synchronously and the rotation direction of the first main shaft 200 and the second main shaft 300, makes 3 First cutter shaft 210 and 2 the second cutter shaft 310 is synchronous and direction rotates, and reaches 3 cutters 500 and rotates forward and 3 cutters 500 Counter-rotational purpose.

As an improvement, 3 first the second main shaft of main shaft 200 and 3 piece, 300 1 minor ticks and to be uniformly distributed around two fixed On plate 100, in terms of axial direction, each first main shaft 200 is respectively positioned between adjacent two second main shaft 300, meanwhile, each second main shaft 300 also are located between adjacent two first main shaft 200, and 3 first the second main shafts of main shaft 200 and 3 piece 300 are distributed in same circumference On.

Using above-mentioned this distribution mode, so that 3 counter-rotational cutters 500 of the cutter 500 and 3 rotated forward are right Claim distribution, so as to all have a reversed cutter 500 corresponding for each forward direction cutter 500, since positive cutter 500 was being slotted The active force that the active force and reversed cutter 500 generated in journey generates is on the contrary, make in positive cutter 500 and reversed cutter 500 Active force offset, guarantee the stability of bellows, the position of bellows avoided to shift and influence the fluting of bellows The generation of quality phenomenon.

It certainly, also can be using other distribution modes, for example, 3 first the second main shafts of main shaft 200 and 3 piece 300 are distinguished It is distributed by the way of being disposed adjacent, is also able to achieve above-mentioned function.

As a further improvement, being equidistant between the first main shaft 200 and the second main shaft 300 of arbitrary neighborhood, so that 3 First the second main shaft of main shaft 200 and 3 300 surround into isosceles triangle and two isosceles triangles it is Chong Die, further protect Having demonstrate,proved the active force that the first main shaft 200 and the second main shaft 300 generate in grooving process can cancel out each other, and improve bellows Fluting quality.

The first spindle bearing holder 202 is provided on above-mentioned 3 the first main shafts 200 and in the first spindle bearing holder 202 On be provided with the first main shaft linking arm 203, first card slot has been extended inwardly to form by its end on the first main shaft linking arm 203 204, first cutter shaft bearing block 211 corresponding with the first spindle bearing holder 202 is provided on the first cutter shaft 210, in the first knife It is provided with first cutter shaft linking arm 212 corresponding with the first main shaft linking arm 203 on bearing housing 211, is connected in the first cutter shaft Surface indentation is formed with the first fixture block 213 respectively inwards for the two sides of arm 212, the first fixture block 213 protrude into the first card slot 204 and with First main shaft linking arm 203 is fixed by screw.

Above-mentioned first spindle bearing holder 202 is connected with the first cutter shaft bearing block 211 using aforesaid way, so that the two dismounts It is convenient, in addition, the first fixture block 213 slides in or out the axial line of 204 moving direction of the first card slot and the first cutter shaft bearing block 211 It is mutually perpendicular to, to improve the bonding strength of the first spindle bearing holder 202 and the first cutter shaft bearing block 211 between the two, keeps away Exempt from the first main shaft linking arm 203 and the first cutter shaft linking arm 212 deforms between the two and influences the first cutter shaft bearing block The generation of 211 normal work phenomenon.

The second spindle bearing holder 302 is provided on above-mentioned 3 the second main shafts 300 and in the second spindle bearing holder 302 On be provided with the second main shaft linking arm 303, second card slot has been extended inwardly to form by its end on the second main shaft linking arm 303 304, second cutter shaft bearing block 311 corresponding with the second spindle bearing holder 302 is provided on the second cutter shaft 310, in the second knife It is provided with second cutter shaft linking arm 312 corresponding with the second main shaft linking arm 303 on bearing housing 311, is connected in the second cutter shaft Surface indentation is formed with the second fixture block 313 respectively inwards for the two sides of arm 312, the second fixture block 313 protrude into the second card slot 304 and with Second main shaft linking arm 303 is fixed by screw.

Above-mentioned second spindle bearing holder 302 is connected with the second cutter shaft bearing block 311 using aforesaid way, so that the two dismounts It is convenient, in addition, the second fixture block 313 slides in or out the axial line of 304 moving direction of the second card slot and the second cutter shaft bearing block 311 It is mutually perpendicular to, to improve the bonding strength of the second spindle bearing holder 302 and the second cutter shaft bearing block 311 between the two, keeps away Exempt from the second main shaft linking arm 303 and the second cutter shaft linking arm 312 deforms between the two and influences the second cutter shaft bearing block The generation of 311 normal work phenomenon.

Corresponding multiple arcs slot is offered in two fixed plates 100, tool is provided with tensioning wheel 800 in each arc groove, Tensioning wheel 800 is located at the first synchronous chain 201 and the second synchronous 301 side of chain and the tensioning wheel 800 is same with first respectively Step chain 201 chain 301 synchronous with second is connected.

The first pine for synchronizing both chains 301 synchronous with second of chain 201 can be adjusted respectively by the setting of multiple tensioning wheels 800 Tight degree avoids the first synchronous chain 201 so that the first tightness for synchronizing the chain 301 synchronous with second of chain 201 reaches preset value Chain 301 synchronous with second occurs too loose or too tight and influences the first normal work for synchronizing the chain 301 synchronous with second of chain 201, protects It has demonstrate,proved first and has synchronized the stability that the chain 301 synchronous with second of chain 201 is driven.

Specific embodiment described herein is only an example for the spirit of the invention.The neck of technology belonging to the present invention The technical staff in domain can make various modifications or additions to the described embodiments or replace by a similar method In generation, however, it does not deviate from the spirit of the invention or beyond the scope of the appended claims.

Claims

1. the power drive mechanism of bellows groover, which is characterized in that including cabinet, main shaft, cutter shaft and cutter, cabinet includes Two fixed plates, main shaft is set in two fixed plates and the both ends of main shaft are connected with two fixed plates respectively, and cutter shaft is set on main shaft And be connected with main shaft, cutter is used for the fluting of bellows and is set to cutter shaft component, and the main shaft energy band movable arbor turns in the same direction It moves and circumferentially rotates cutter, the main shaft includes the first main shaft and the second main shaft, and more first main shafts pass through the first synchronous chain Be sequentially connected, second main shaft is sequentially connected by the second synchronous chain, more first main shafts can rotate synchronously and with more it is same The rotation direction of the second main shaft of rotation is walked on the contrary, being provided with spindle bearing holder on main shaft and being provided on spindle bearing holder Main shaft linking arm, offers card slot on main shaft linking arm, cutter shaft bearing block is provided on cutter shaft and on cutter shaft bearing block It is provided with cutter shaft linking arm, cutter shaft linking arm is provided with fixture block, the fixture block can be arranged in card slot, and the more main shafts are equal Even to be looped around between two fixed plates, cutter shaft includes the first cutter shaft corresponding with first main shaft and corresponding with second main shaft The second cutter shaft, be provided with the first drive chain between first main shaft and first cutter shaft, in second main shaft and It is provided with the second drive chain between second cutter shaft, tool apron is provided on cutter shaft, the cutter is set on tool apron, on tool apron The both ends for being provided with Synchronization Component and the Synchronization Component are connected with tool apron and cutter shaft respectively, and the cutter shaft can be driven by tool apron Cutter circumferentially rotates and the Synchronization Component can make cutter and bellows synchronous shift.

2. the power drive mechanism of bellows groover according to claim 1, which is characterized in that the Synchronization Component packet Elastic component and guide part are included, the elastic component is sheathed on cutter shaft and the both ends of elastic component are connected with tool apron and cutter shaft respectively, institute Guide part is stated to be set on the excircle of tool apron, when the conveying speed of bellows fluctuates in a certain range, the guide part Can make tool apron with bellows in the axial direction synchronizing moving and make tool apron drive elastic component compression or reset.

3. the power drive mechanism of bellows groover according to claim 2, which is characterized in that the guide part includes Two are set to the guide part on tool apron, and mounting groove and the mounting groove are offered on tool apron between two guide parts, described Cutter is set in mounting groove, and be connected with guide part guiding arc, the guiding arc and guiding are provided on the excircle of tool apron Portion is contacted with bellows.

4. the power drive mechanism of bellows groover according to claim 1 or 2, which is characterized in that the cutter shaft The shape of cross section is in polygon, fixing groove corresponding with cutter shaft is offered on tool apron, the cutter shaft is arranged in fixing groove.

5. the power drive mechanism of bellows groover according to claim 4, which is characterized in that first main shaft and Second main shaft is successively spaced and is uniformly distributed around in two fixed plates, between the first main shaft and the second main shaft of arbitrary neighborhood It is equidistant.

6. the power drive mechanism of bellows groover according to claim 5, which is characterized in that in two fixed plates Several arc grooves are offered, are provided with tensioning wheel in each arc groove, the tensioning wheel is located at the first synchronous chain and the Two synchronous chain sides and chain synchronous with first and the second synchronous chain are connected respectively for the tensioning wheel.