Abstract:
The present invention refers to a peristaltic pump, especially refers to a linear peristaltic pump for precise and quantitative delivery of fluid, comprising a base, wherein, a lateral seat for fixing a flexible tube is provided on the base, a linear reciprocating movement mechanism is provided below the flexible tube; a sliding block is provided on the linear reciprocating movement mechanism, adapted for releasing and squeezing a flexible tube to moves up and down; a backflow preventing device is fixed on the base arranged close to the linear reciprocating movement mechanism. By adopting the above structure, a new operational principle of linear type is formed, and the structure of traditional rotary peristaltic pump is improved. The flexible tube is rarely abraded; it is easy to disassemble and assemble the flexible tube; and the feed liquid does not contact with the device.

Description:
TECHNICAL FIELD 
       [0001]    The present invention refers to a peristaltic pump, especially refers to a linear peristaltic pump for precise and quantitative delivery of fluid. 
       BACKGROUND OF THE INVENTION 
       [0002]    A peristaltic pump functions like fingers holding a fluid filled tube. The fluid in the tube moves forward, as fingers slide forward. A peristaltic pump also adopts this principle by only replacing the fingers by a contact roller. The pump of fluid is achieved by alternately squeezing and releasing the flexible delivery tube of the pump. Like the fingers squeezing a flexible tube, with the movement of the fingers, a negative pressure is formed in the tube, therefore the fluid flows. A peristaltic pump is to form a “pillow” shaped fluid in the pump tube between two rolls. In industrial production, in many cases they need to add the liquid to the production apparatus by a peristaltic pump, so that the fluid may be remained in the flexible tube, or the speed of introducing fluid into the flexible tube is not fast enough. So that it is necessary to design an apparatus for squeezing the fluid in the flexible tube, on one hand, to increase the speed of introducing fluid into the flexible tube by alternately squeezing, on the other hand, to discharge the remaining fluid in the flexible tube by alternately squeezing, at the same time, the liquid delivery quantity can be accurate quantitative controlled. 
         [0003]    Chinese patent CN 203161500 U discloses a linear peristaltic pump, comprising a frame, a lifting motion, an infusion set, an infusion flexible tube, a linear drive module, an on-off valve, and an extrusion roller assembly, wherein, the linear drive module is assembled on the frame, the infusion set is connected to the lifting motion, the on-off valve is fixed on the frame, the infusion flexible tube is assembled on the infusion set and passes through the on-off valve, the extrusion roller assembly is connected on the linear drive module. The invention increases the life time of the infusion flexible tube, occupied less space, and improves the accuracy of the delivery of fluid. But the accurate quantitative control of the liquid delivery quantity cannot be achieved by the invention, besides, the invention cannot prevent backflow very well. 
       SUMMARY OF THE INVENTION 
       [0004]    The technical problem to be solved by the present invention is to provide a linear peristaltic pump for precise and quantitative delivery of fluid. 
         [0005]    In order to solve the above mentioned technical problem, the present invention provides a linear peristaltic pump for precise and quantitative delivery of fluid, comprising a base, a lateral seat for fixing a flexible tube is provided on the base, a linear reciprocating movement mechanism is provided below the flexible tube; 
         [0000]    a sliding rod base is provided on the linear reciprocating movement mechanism, a sliding rod base shaft is fixed on the sliding rod base, a sliding block is sleeved on the sliding rod base shaft; a pin roller is provided at the top end of the sliding block, adapted for squeezing a flexible tube to allow fluid in the tube to move forwards the pin roller, the pin roller is in contact with the flexible tube, a detection device for detecting a position of sliding rod base is provided on the base;
 
a guide rod parallel with the flexible tube is fixed on the lateral seat, a through hole adapted for coordinating with the guide rod is provided on the sliding block, the guide rod is arranged to extend through the through hole on the sliding block, and both ends of the guide rod are connected with a moving device for moving the sliding block up and down;
 
a backflow preventing device is fixed on the base arranged close to the linear reciprocating movement mechanism.
 
         [0006]    Further, the linear reciprocating movement mechanism comprises a rotation motor fixed on the base; a rotation shaft of the rotation motor is in transmission connection with a guide screw through a shaft coupling, the guide screw is provided parallel with and below the guide rod; a nut adapted for moving in linear direction is provided on the guide screw, the nut is fixed to the sliding rod base. 
         [0007]    Further, a guide screw cover is provided between the nut and the sliding rod base. 
         [0008]    Further, the moving device comprises connecting seats respectively fixed on each end of the guide rod, the left connecting seat of the guide rod is rotatably connected to the base, the right connecting seat of the guide rod is rotatably connected to a strap drive; the strap drive is fixed with a driven gear, the driven gear is engaged with a driving gear, and the driving gear is fixed on the rotation shaft of a first motor. 
         [0009]    Further, the detection device comprises a photoelectric switch fixed on the base below both ends of the guide screw, and a photoelectric isolation piece fixed below the sliding rod base. 
         [0010]    Further, the backflow preventing device comprises a sliding bush bracket and a second motor fixed on the sliding bush bracket, a transmission block is fixed on the second motor, a clamping tube fixing block is fixed on the transmission block, a sliding bush shaft is arranged to extend through the sliding bush bracket and is fixed on the clamping tube fixing block, a clamping tube cover is fixed on the other side of the sliding bush shaft; a detection device for detecting a position of clamping tube cover is provided between the clamping tube fixed block and the base. 
         [0011]    Further, the detection device comprises a photoelectric isolation piece fixed below the clamping tube fixed block, and a photoelectric switch adapted for coordinating with the photoelectric isolation piece fixed on the base. 
         [0012]    Further, a limiting shaft is provided below the clamping tube fixing block, the limiting shaft is fixed on the sliding bush bracket. 
         [0013]    Further, a cover plate is fixed on the lateral seat above the flexible tube. 
         [0014]    By adopting the above structure, a new operational principle of linear type is formed, and the structure of traditional rotary peristaltic pump is improved. Besides, the flexible tube is rarely abraded, which greatly reduces the risk of the inner wall falling off; it is easy to disassemble and assemble the flexible tube, which is advantageous for cleaning and sterilizing bacteria; the feed liquid does not contact with the device, so it is safer. The adjustment of the filling quantity is extremely simple, and it is relatively stable for packing repeatedly large quantity feed liquid; soft start can be set to avoid of splash or bubble phenomenon, and it can also realize immediate stopping and suction in order to avoid of drippage. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The invention will be described in greater detail with references to the appended drawings in order to make the invention and the advantages understood better. 
           [0016]      FIG. 1  is a general assembly view of the present invention. 
           [0017]      FIG. 2   a  and  FIG. 2   b  are structure schematic views of linear reciprocating movement mechanism and moving device for moving sliding block up and down of the present invention. 
           [0018]      FIG. 3  is a structure schematic view of the guide screw cover of the present invention. 
           [0019]      FIG. 4   a  and  FIG. 4   b  are structure schematic views of sliding block of the present invention. 
           [0020]      FIG. 5   a - FIG. 5   c  are structure schematic views of backflow preventing device of the present invention. 
           [0021]      FIG. 6   a - FIG. 6   e  are schematic views of the working process of the present invention. 
         Wherein, 
         [0022]      1 . base,  2 . rotation motor,  3 . guide screw,  4 . sliding rod base,  5 . guide rod,  6 . flexible tube,  7 . flexible tube connector,  8 . guide screw cover,  9 . sliding block,  10 . sliding rod base cover,  11 . strap drive,  12 . driven gear,  13 . driving gear,  14 . first motor,  15 . left connecting seat of the guide rod,  16 . right connecting seat of the guide rod,  17 . sliding rod base shaft,  18 . attachment bracket,  19 . second motor,  20 . sliding bush bracket,  21 . limiting shaft,  22 . clamping tube fixing block,  23 . sliding bush shaft,  24 . clamping tube cover,  25 . transmission block,  26 . transmission shaft,  27 . bearing,  28 . left lateral seat,  29 . right lateral seat,  30 . cover plate,  31 . shaft coupling,  32 . photoelectric switch,  33 . photoelectric isolation piece,  301 . nut,  901 . rotation shaft,  902 . through hole,  903 . pin roller 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0023]    As shown in  FIG. 1 , a linear peristaltic pump for precise and quantitative delivery of fluid of the present invention, comprising a base  1 , a lateral seat for fixing a flexible tube  6  is provided on the base  1 , the lateral seat comprises a left lateral seat  28  and a right lateral seat  29 , the flexible tube  6  is fixed between the left lateral seat  28  and the right lateral seat  29 . Flexible tube connectors  7  for connecting perfusion tube are provided on the both ends of the flexible tube  6 . A cover plate  30  is fixed between the left lateral seat  28  and the right lateral seat  29  above the flexible tube, the cover plate  30  on one hand could well protect the flexible tube  6  from damage. 
         [0024]    A linear reciprocating movement mechanism is provided below the flexible tube  6 . As shown in  FIG. 1 ,  FIG. 2   a  and  FIG. 2   b , the linear reciprocating movement mechanism comprises a rotation motor  2  fixed on the basel, a rotation shaft of the rotation motor  2  is in connection with a guide screw  3  through a shaft coupling  31 , the guide screw  3  is provided parallel with and below the guide rod  5 ; the guide rod  5  is parallel with the flexible tube  6 . A nut  301  adapted for moving in linear direction is provided on the guide screw  3 , the nut  301  is fixed to the sliding rod base  4 , the nut  301  and sliding rod base  4  can be driven by guide screw  3  to move along the guide rod  5 . The rotation of the guide screw  3  is driven by the rotation motor  2 , the sliding rod base  4  is adapted for coordinating with the guide screw, therefore, the sliding rod base  4  moves back and forth along the guide screw. In this way, the sliding rod base  4  can be driven by rotation motor  2  to move along the linear direction parallel with the flexible tube, therefore, the rotation angle of the guide screw can be controlled by the rotation motor  2 , and the movement of the sliding rod base and the sliding block can be controlled, so that the liquid delivery quantity can be accurately and quantitatively controlled. 
         [0025]    Further, a guide screw cover  8  is provided between the guide screw  3  and the sliding rod base  4 , the structure of the guide screw cover  8  is shown in the  FIG. 3 . The guide screw  3  and nut  301  are disposed at the inner side of the guide screw cover  8 , the sliding rod base  4  extends into the guide screw cover  8  from the both sides thereof and fixed with the nut  301  inside the guide screw cover  8 . On one hand, this can effectively prevent dust from falling into the screw  3 , so as to allow the screw to have a well long-term operation, on the other hand, it can guide the linear reciprocating movement of the sliding rod base  4 . 
         [0026]    In order to squeeze the fluid in the flexible tube, a sliding rod base cover  10  is provided on the upper end of the sling rod base  4 , a sliding rod base shaft  17  is fixed on the sling rod base cover  10 , a sliding block  9  is sleeved on the sliding rod base shaft  17 , the sliding block  9  moves up and down along the sliding rod base shaft  17 . As shown in  FIG. 4   a  and  FIG. 4   b , a rotatable pin roller  903  is provided at the top end of the sliding block  9 , the pin roller  903  is fixed on the rotation shaft  901 , the rotation shaft  901  passes through the sliding block  9  at the top thereof, in this way, the sliding block  9  can rotate around the rotation shaft  901 . The pin roller  903  is in contact with the flexible tube  6 , so that the state that the sliding block  9  squeezes the flexible tube  6  and releases the flexible tube  6  can be achieved by moving the sliding block up and down. 
         [0027]    In order to achieve the reciprocating movement of the sliding block  9 , a through hole  902  adapted for coordinating with the guide rod  5  is provided on the sliding block  9 , there are two guide rods, which are arranged parallel with each other. The guide rod  5  is arranged to extend through the through hole  902  on the sliding block  9 , and both ends of the guide rod  9  are connected with a moving device for moving the sliding block up and down. 
         [0028]    As shown in  FIG. 2   a  and  FIG. 2   b , the moving device for moving the sliding block up and down comprises connecting seats fixed on both ends of the guide rod  5 , the left connecting seat of the guide rod  15  is rotatably connected to the base by an attachment bracket  18 , the right connecting seat of the guide rod  16  is rotatably connected to a strap drive  11 . The strap drive  11  is fixed with a driven gear  12 , the driven gear  12  is engaged with a driving gear  13 , and the driving gear  13  is fixed on the rotation shaft of the first motor  14 . Because both ends of the guide rod  5  is in rotatable connection, when the first motor  14  rotates, the driving gear  13  drives the driven gear  12  to rotate, therefore the guide rod  5  moves downward; in this way, the sliding block  9  on the guide rod  5  moves downward, meanwhile, the sliding block  9  moves downward along the sliding rod base shaft  17 , the distance between the sliding block  9  and the sliding rod base cover  10  is decreased. 
         [0029]    In order to achieve the linear reciprocating movement, a detection device for detecting a position of sliding rod base is provided on the base, the detection device comprises a photoelectric switch  32  fixed on the base below both ends of the guide screw, and a photoelectric isolation piece  33  piece fixed below the sliding rod base  4 , when the sliding rod base  4  with sliding block  9  moves to the position of both ends of the guide screw, the photoelectric switch  32  is separated by the photoelectric isolation piece  33 , therefore the position of the sliding rod base  4  is detected. When the left side photoelectric switch detects the sliding rod base  4 , the rotation motor  2  drives the guide screw  3  so as to drive the sliding rod base  4  to move rightward; when the right side photoelectric switch detects the sliding rod base  4 , the rotation motor  2  drives the guide screw  3 , so as to drive the sliding rod base  4  to moves leftward. 
         [0030]    Further, in order to prevent the backflow when the rod base  4  moves leftward a backflow preventing device is fixed on the right side of the linear reciprocating movement mechanism. As shown in  FIG. 5   a - FIG. 5   c , the backflow preventing device comprises a second motor  19  fixed on the sliding bush bracket  20 , a transmission block  25  is fixed on the second motor  19 , a clamping tube fixing block  22  is fixed on the transmission block  25 , a sliding bush shaft  23  is arranged to extend through the sliding bush bracket  20  and is fixed on the clamping tube fixing block  22 , a clamping tube cover  24  is fixed on the other side of the sliding bush shaft  23 . The transmission block  25  is fixed with the second motor  19  by transmission shaft  26 , a bearing  27  is provided between the transmission shaft and the transmission block  25 . In this way, the transmission block  25  is driven to rotates by the second motor  19 , therefore the clamping tube fixing block  22 , the sliding bush shaft  23  and the clamping tube cover  24  are driven to move up and down. When the right side photoelectric switch detects the sliding rod base  4 , the second motor  19  is started, so that the clamping tube cover  24  moves upward and squeezes the flexible tube  6 , in this way, the fluid in the flexible tube  6  will not flow back. 
         [0031]    In order to determine the position when the clamping tube cover moves up and down, a detection device for detecting a position of clamping tube cover is provided between the clamping tube fixed block  22  and the base  1 . As shown in  FIG. 5   a  and  FIG. 6   a , the detection device comprises a photoelectric isolation piece  33  fixed below the clamping tube fixed block  22 , and a photoelectric switch  32  adapted for coordinating with the photoelectric isolation piece  33  fixed on the base. When the clamping tube fixing block  22 , the sliding bush shaft  23  and the clamping tube cover  24  move up and down, a staggered and separated state of the photoelectric isolation piece  33  and the photoelectric switch  32  will appear, so as to realize a detection of a position of clamping tube cover. 
         [0032]    Further, in order to prevent the clamping tube fixed block  22  from moving down too much, a limiting shaft  21  is provided below the clamping tube fixing block  22 , the limiting shaft  21  is fixed on the sliding bush bracket  20 . 
         [0033]    The working process of the present invention is as follows:  FIG. 6  is the star state of the present invention, the sliding rod base  4  and the sliding block  9  are disposed at the left side of the base  1 , the strap drive  11  connected to the guide rod  5  is in a heeling condition, and the distance between the sliding rod base cover  10  and the sliding block  9  is short, and the sliding block  9  does not press on the flexible tube. 
         [0034]      FIG. 6   b  is a schematic view showing the rotation motor  2  drives the sliding base  4  and the sliding block  9  to move right to squeeze the flexible tube. The first motor  14  of the moving device for moving the sliding block up and down is started to rotate the strap drive  11  by the cooperation of the driven gear  12  and the driving gear  13 , so that the strap drive  11  is in a vertical position, therefore the sliding block  9  moves upward, the distance between the sliding rod base cover  10  and the sliding block  9  becomes longer, it can be seen from the different exposed lengths of the sliding rod base shafts  17  in  FIG. 6   a  and  FIG. 6   b . the rotation of the guide screw is driven by rotation motor  2 , the sliding base  4  and the sliding block  9  move rightward, the sliding block  9  squeezes the flexible tube  6 , therefore the sliding block  9  squeezes the fluid in the flexible tube  6  from left to right. 
         [0035]      FIG. 6   c  shows that the sliding rod base  4  moves to the right end of the guide screw  3 , meanwhile, the photoelectric switch  32  at the right end of the guide screw is separated by the photoelectric isolation piece  33  below the sliding rod base  4 , therefore the position that the sliding rod base  4  moves to the right end of the guide screw is detected. The rotation motor  2  is controlled stop working. 
         [0036]    In order to prevent the fluid reflux after the fluid is squeezed, as shown in  FIG. 6   d , the second motor  19  is started, the clamping tube fixing block  22 , the sliding bush shaft  23  and the clamping tube cover  24  are driven to move upward (it can be seen from the exposed length of the sliding bush shaft  23  between sliding bush bracket  20  and the clamping tube cover  24  in  FIG. 6   c  and  FIG. 6   d ), so as to allow the clamping tube cover  24  to squeeze the flexible tube  6  and prevent the fluid from refluxing. 
         [0037]    Finally, as shown in  FIG. 6   e , the first motor  14  is started, and the driving gear  13  drives the driven gear  12  to rotate, therefore the guide rod  5  moves downward, and the sliding block  9  on the guide rod  5  moves downward, meanwhile, the sliding block  9  moves downward along the sliding rod base shaft  17 . In this way, the sliding block  9  is separated from the flexible tube  6  then the rotation motor  2  drives the guide screw in reverse direction, so as to drive the sliding rod base  4  and sliding block  9  to move leftward. When moving to the left end, the photoelectric switch  32  at the left end of the guide screw is separated by the photoelectric isolation piece  33  below the sliding rod base  4 , therefore the position that the sliding rod base  4  moves to the left end of the guide screw is detected. At this time, the second motor  19  is started, the clamping tube fixing block  22 , the sliding bush shaft  23  and the clamping tube cover  24  are driven to move downward, and the apparatus then returns to the state shown in  FIG. 6   a.    
         [0038]    The description above refers to a reciprocating squeezing of fluid in the flexible tube, according to the  FIG. 6   a - FIG. 6   e , a continuously reciprocating squeezing of fluid in the flexible tube can be achieved. 
         [0039]    Of course, the linear reciprocating movement mechanism in the present invention can also adopt a screw thread pair or a combined rack and gear, the detection device for detecting a position of sliding rod base can also adopt a shutter and an over travel-limit switch, such modifications could be derived without departing from the scope of the invention. 
         [0040]    It needs to declare that, the above mentioned summery of the invention and the embodiments are intended to provide a practical application of the technical solution of the present invention, which do not constitute limitation of the present invention. It is obviously to the skilled person in the art that, various modifications could be derived without departing from the spirits and the effects of the invention. Therefore, the protection scope of the present invention is subject to the claims.