Precision peristaltic metering pump and device thereof

Abstract

A precision peristaltic metering pump comprises a base, a case structure, a differential device, and a hose. The case structure is disposed on the base and has a lateral wall. The differential device comprises a first member, a second member, a plurality of planet gears, and a sun gear, wherein the first member has a first internal gear and a plurality of rollers. The second member has a second internal gear. Each planet gear has a first external gear and a second external gear. The first and second external gears mesh with the first and second internal gears respectively. The sun gear pivotally connects with the base and meshes with the plural planet gears. Hence, while the sun gear drives the planet gears, the first member is in rotation relative to the second member. The hose is pushed by the rollers so as to urge the lateral wall.

What is claimed is: 
     
         1 . A precision peristaltic metering pump comprising:
 a base;   a case structure, disposed on the base and having a lateral wall, an accommodating space being defined by the lateral wall;   a differential device, disposed in the accommodating space, comprising:
 a first member, having a first internal gear and a plurality of rollers; 
 a second member, having a second internal gear, the first member being correspondingly coupled to the second member; 
 a plurality of planet gears, one end of each planet gear having a first external gear portion and the other end a second external gear portion, respectively, the first external gear portion meshing with the first internal gear, the second external gear portion meshing with the second internal gear; and 
 a sun gear, pivotally connecting with the base and meshing with the plurality of planet gears; and 
   a hose, disposed between the lateral wall and the plurality of rollers and tightly urged to the lateral wall by the plurality of rollers.   
     
     
         2 . The precision peristaltic metering pump according to  claim 1 , wherein the first member has a plurality of protruding rotors, the plurality of rollers being installed on the plurality of protruding rotors. 
     
     
         3 . The precision peristaltic metering pump according to  claim 2 , wherein the differential device further has a planet arm set and a plurality of pins, the planet arm set having a first planet arm and a second planet arm, the plurality of pins being corresponding to the plurality of planet gears respectively, the planet gears pivotally connecting with the second planet arm through the pins, the rollers pivotally connecting with a position between the first planet arm and the first member through the rotors. 
     
     
         4 . The precision peristaltic metering pump according to  claim 3 , wherein the sun gear pivotally connects with the center of the second planet arm. 
     
     
         5 . The precision peristaltic metering pump according to  claim 4 , wherein the differential device has three horizontal planet gears. 
     
     
         6 . The precision peristaltic metering pump according to  claim 1  further comprising a motor in order to drive the sun gear. 
     
     
         7 . A precision peristaltic metering pump device comprising:
 a base;   a case structure, disposed on the base and having a lateral wall, an accommodating space being formed by the lateral wall;   a differential device, disposed in the accommodating space and comprising:
 a first member, having a first internal gear and a plurality of rollers; 
 a second member, having a second internal gear, the first member being corresponding to the second member; 
 a plurality of planet gears, each planet gear having a first external gear and a second external gear, the first external gear meshing with the first internal gear, the second external gear meshing with the second internal gear; and 
 a sun gear, pivotally connecting with the base and meshing with the plurality of planet gears; 
   a hose, disposed between the lateral wall and the plurality of rollers and tightly urged to the lateral wall by the plurality of rollers;   a flexible fastening member, female-connecting with the hose; and   a holding member, clamping the flexible fastening member, the flexible fastening member being squeezed by the holding member in order to tightly wrap around the hose.   
     
     
         8 . The precision peristaltic metering pump device according to  claim 7 , wherein the hose has an inlet portion and an outlet portion, the flexible fastening member female-connecting with the inlet portion and the outlet portion of the hose, the flexible fastening member being squeezed by the holding member in order to tightly wrap around the inlet portion and the outlet portion. 
     
     
         9 . The precision peristaltic metering pump device according to  claim 8 , wherein the one end of the holding member forms two bent arm structures that are corresponding to each other, the other end of the holding member forming a U-type clamping structure, the two ends of the U-type clamping structure connecting with the two bent arm structure respectively. 
     
     
         10 . The precision peristaltic metering pump device according to  claim 9 , wherein the U-type clamping structure clamps the flexible fastening member from the case structure toward the flexible fastening member, the flexible fastening member being a ringer that has a pre-determined width. 
     
     
         11 . The precision peristaltic metering pump device according to  claim 7 , wherein a plurality of hose limits are between the case structure and the second member, a limit portion being between the plurality of hose limits. 
     
     
         12 . The precision peristaltic metering pump device according to  claim 7 , wherein the first member has a plurality of protruding rotors, the plurality of rollers being installed on the plurality of protruding rotors. 
     
     
         13 . The precision peristaltic metering pump device according to  claim 12 , wherein the differential device further has a planet arm set and a plurality of pins, the planet arm set having a first planet arm and a second planet arm, the plurality of pins being corresponding to the plurality of planet gears respectively, the planet gears pivotally connecting with the second planet arm through the pins, the rollers pivotally connecting with a position between the first planet arm and the first member through the rotors. 
     
     
         14 . The precision peristaltic metering pump device according to  claim 13 , wherein the sun gear pivotally connects with the center of the second planet arm. 
     
     
         15 . The precision peristaltic metering pump device according to  claim 14 , wherein the differential device has three horizontal planet gears. 
     
     
         16 . The precision peristaltic metering pump device according to  claim 7  further comprising a motor in order to drive the sun gear.