US20130177463A1

US20130177463A1 - Precision peristaltic metering pump and device thereof

Info

Publication number: US20130177463A1
Application number: US13/667,291
Authority: US
Inventors: Chen -Tse Cheng; Ping-Shih Wang
Original assignee: Cheshire Electric Co LLC
Current assignee: Cheshire Electric Co LLC
Priority date: 2012-01-11
Filing date: 2012-11-02
Publication date: 2013-07-11
Also published as: TWM434834U

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.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a precision peristaltic metering pump and a device thereof; in particular, to a precision peristaltic metering pump that has a differential device and a device thereof.
2. Description of Related Art
Peristaltic pump functions to deliver fluid. Peristalsis is a phenomenon of fluid delivery under normal pressure environment, and such peristalsis is just like the delivery phenomena of the intestines and stomach of a human being. For a peristaltic tubing pump, it is to deliver fluid via the peristalsis of the wall of a hose. The peristaltic tubing pump is characterized by that fluid only contacts with the inner wall of the hose and hose fittings and does not touch other active components, units or fluids in the pump so as to lower down the contaminations as possible as it can. The peristaltic tubing pump is applied to not only labs and multiple applications in industry, but drip liquid, blood transfusions and humoral in dialysis machine of hospital. Prior peristaltic pump has a disc and a plurality of roller sets pivotally disposed on the periphery of the disc in equidistance, and the surface of each roller bulges out from the periphery of the disc. The roller sets are driven by motor for circular motions. Through push and releasing soft hose of the roller sets, pulse intermittent thrusts may happen to deliver the fluid in the soft hose. However, the prior way of the roller sets pushing the soft hose may often cause varied unstable flow rates, so that if an accurate flow rate is a must, the prior pump will be failed.
Therefore, the inventor had studied related technologies so as to produce the present invention that improve the disadvantages of the prior arts.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a precision peristaltic metering pump, which accurately control the intermittent pulsation between rollers and a hose in order to precisely control the output flow quantity of fluid in the hose.
The other object of the present invention is to provide the precision peristaltic metering pump device, a flexible fastening member is squeezed by a holding member to wrap around the hose so as to prevent that the hose slips. The holding member and the flexible fastening member are simple, easily assembled, etc.
In order to achieve the aforementioned objects, according to an embodiment of the present invention, the present invention 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 external gear meshes with the first internal gear, the second external gear meshes with the second internal gear. The sun gear pivotally connects with the base and meshes with the plurality of planet gears. Hence, while the sun gear drives the planet gears, the first member is in rotation relative to the second member. Meanwhile the hose is pushed by the rollers so as to urge the lateral wall.
In addition, the precision peristaltic metering pump cooperates with a flexible fastening member and a holding member to become a precision peristaltic metering pump device. The flexible fastening member is squeezed by the holding member to wrap around the hose.
The present invention has following advantages listed below. The precision peristaltic metering pump of the present invention adopts a differential device to accurately control the speed of the rollers squeezing the hose for continuously and quantitatively controlling a precision flow rate. Additionally, due to the simple structure of the differential device, the advantages of lower manufacturing cost and difficulty are approached.
In order to further the understanding regarding the present invention, the following embodiments are provided along with illustrations to facilitate the disclosure of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a schematic exploded view of the precision peristaltic metering pump of the present invention;

FIG. 1B illustrates a schematic exploded view of another view angle of the precision peristaltic metering pump of the present invention;

FIG. 2 illustrates a schematic assembled view of the precision peristaltic metering pump of the present invention;

FIG. 3 illustrates a schematic top sectional view of the precision peristaltic metering pump of the present invention;

FIG. 4 illustrates a schematic exploded view of the precision peristaltic metering pump device of the present invention;

FIG. 5 illustrates a schematic assembled view of the precision peristaltic metering pump device of the present invention; and

FIG. 6 illustrates a schematic top sectional view of the precision peristaltic metering pump device of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The aforementioned illustrations and following detailed descriptions are exemplary for the purpose of further explaining the scope of the present invention. Other objectives and advantages related to the present invention will be illustrated in the subsequent descriptions and appended drawings.
With references to FIG. 1A to FIG. 2, the present invention provides a precision peristaltic metering pump. As shown in FIG. 1, the precision peristaltic metering pump 1 includes a base 10, a case structure 20, a differential device 30, and a hose 40.
The case structure 20 is disposed on the base 10 and has a lateral wall 201, an accommodating space 202 is defined by the lateral wall 201, so that the differential device 30 is accommodated in the accommodating space 202.
The differential device 30 includes a first member 301, a second member 302, a plurality of planet gears 303, and a sun gear 304; wherein the sun gear 304 pivotally connects with the base 10 and meshes with the plurality of planet gears 303. The first member 301 has a first internal gear 301 a. The second member 302 has a second internal gear 302 a. Each planet gear 303 has a first external gear 303 a and a second external gear 303 b. The first external gear 303 a meshes with the first internal gear 301 a, the second external gear 303 b meshes with the second internal gear 302 a. Hence, while the sun gear 304 drives the planet gears 303, the first member 301 is in rotation relative to the second member 302, and a plurality of rollers 301 b may be in rotation as well as the first member 301. Meanwhile the hose 40 is pushed by the rollers 301 b so as to urge the lateral wall 201. By the means of pushing and releasing the hose 40, the fluid inside the hose 40 is then driven to move. For example, a section, between two rollers 301 b, of the hose 40 has some fluid, and the hose 40 may be squeezed by the movement of the rollers 301 b in order to deliver the fluid. Continuously, the fluid is exhausted to outside of the hose 40 while the rollers 301 b release the hose 40, in another word, the hose 40 is not squeezed by the rollers 301 b. After that, the following fluid will be input to the hose 40 constantly. According to aforesaid, the precision peristaltic metering pump 1 of the present invention adopts the differential device 30 to accurately control the speed of the rollers 301 b squeezing the hose 40 for continuously and quantitatively controlling a precision flow rate. In addition, due to the simple structure of the differential device 30, the advantages of lower manufacturing cost and difficulty are approached.
Following will describe the preferred embodiments in detail. With references to FIG. 1A and FIG. 1B, which illustrate a schematic exploded view of the precision peristaltic metering pump of the present invention and a schematic exploded view of another view angle of the precision peristaltic metering pump of the present invention. As shown in FIG. 1A and FIG. 1B, the first member 301 of the precision peristaltic metering pump 1 has a plurality of protruding rotors 301 c, the plurality of rollers 301 b are installed on the plurality of protruding rotors 301 c by means of female-connection, adhering, etc. Therefore, the rollers 301 b will be in rotation as well as the first member 301. For the present preferred embodiment, the rotors 301 c protruding upward are formed on the first member 301 by one piece. Through the two-stage design of the rotors 301 c and the rollers 301 b, such worn rollers 301 b are easily replaced without changing the whole first member 301 so as to save time, labor and cost.
Except for the first member 301, the second member 302, the plurality of planet gears 303, and the sun gear 304, the differential device 30 has a planet arm set 305 and a plurality of pins 306; the planet arm set 305 has a first planet arm 305 a and a second planet arm 305 b, the rollers 301 b pivotally connects with a position between the first planet arm 305 a and the first member 301 through the rotors 301 c. As shown in FIG. 1A, for the preferred embodiment, the differential device 30 has three horizontal planet gears 303, and the three planet gears 303 are horizontally disposed on the peripheral of the sun gear 304 with the arrangement of a regular triangle, the pins 306 are corresponding to the planet gears 303 respectively, and the planet gears 303 pivotally connect with the second planet arm 305 b through the pins 306. Hence, the differential device 30 is easily assembled, hardly out of order and stable. In other words, the movement of the roller can be effectively controlled. Additionally, the sun gear 304 pivotally connects with the center of the first planet arm 305 a, and the centers of the sun gear 304 and the first planet arm 305 a are in alignment, so that the planet gears 303 are driven precisely, then vibrations and noises are reduced either. As it can be seen, the differential device 30 is able to accurately transmit power and position the rotation of the first member 301, that is, the rotation of the rollers 301 b relative to the hose 40 can be positioned in order to accurately, quantitatively and continuously let the fluid flow through the hose 40. The second planet arm 305 b is disposed on the base 10. The planet gears 303 are mounted on the base 10 through the second planet arm 305 b. Such that, the planet gears 303 are able to firmly combine with the sun gear 304 pivotally connecting with the base 10. Further, the first member 301 prominently has an axis 301 d between the first member 301 and the case structure 20 and located in the center of the first member 301. The axis 301 d functions to support in order to firmly install the case structure 20 on the second member 302 and rotate the first member 301 with respect to the second member 302.
With reference to FIG. 2, which illustrates a schematic assembled view of the precision peristaltic metering pump of the present invention. As shown in FIG. 2, the precision peristaltic metering pump 1 further has a motor 50, and the motor 50 has a transmission axis (not shown in figure). The transmission axis may drive the sun gear 304 to output a pre-determined rotational speed. The planet gears 303 mesh with the sun gear 304. The motor 50 can be a DC motor, such as commutator motor or brushless motor, an AC motor, such as induction motor or synchronous motor, a stepping motor, a linear motor, ultrasonic motor, etc. For the preferred embodiment, the motor 50 is a stepping motor, and the principle of electric split exciting can then be applied to control the pulse voltage and electrifying time of each phase. Hence, the stepping angle of the stepping motor is tinier for further position control. In another word, the precision peristaltic metering pump 1 uses the relationships of an accuracy, a fixing angle, rotation, and control signals of the stepping motor to drive the rollers 301 b, then the rollers 301 b may squeeze the hose 40 to quantitatively deliver fluid. Therefore, the precision peristaltic metering pump 1 not only drives the differential device 30 through the stepping motor for reaching higher accuracy requests of flow rates, but also digitizes, controls and records the quantity of delivered fluid. With references to FIG. 1B and FIG. 2, as shown in FIG. 1B, the second member 302 is fastened to the base 10 through a plurality of bolts (not numbered in figure). The second external gears 303 b of the planet gear 303 mesh with the second internal gear 302 a of the second member 302, therefore the planet gears 303 may be in rotation synchronous to the sun gear 304 but with different rotation directions via non-eccentric output power while the sun gear 304 is in rotation. Meanwhile, since the second member 302 is not in movement and the first external gears 303 a of the planet gears 303 mesh with the first internal gear 301 a of the sun gear 304 of the first member 301, the first member 301 may be in rotation synchronous to the sun gear 304, and the rotation directions of the first member 301 and the sun gear 304 are the same. In other words, through that the planet gears 303, disposed on the planet arm set 305, can be both in revolution and rotation between the second member 302 and the sun gear 304, the direction of the rotation of the sun gear 304 is the direction of the rotation of the rollers 301 b.
It is to be noted that the tooth number of the first external gear 303 a of the planet gears 303 may be the same as or different than the tooth number of the second external gear 303 b of the planet gears 303. In case of different tooth numbers, a variety of rotation ratios can then be produced. That is, to meet different demands, different rates of tooth numbers of the planet gears 303 can be designed. In addition, the touching areas are larger while the sun gears 304, the planet gears 303, the first member 301, and the second member 302 mesh with each other, the stress accepted by each gear is lowered. Hence, the differential device 30 is able to accept larger power input (high power horsepower input), tooth-broken may not be happening very easily, the structure is compact, and the performance is stable as well.
With reference to FIG. 3, which illustrates a schematic top sectional view of the precision peristaltic metering pump of the present invention. As shown in FIG. 3, in practice, a motor (not shown in figure) drives the differential device 30 to rotate, the rollers 301 b and the lateral wall 201 both squeeze the hose 40 in order to let fluid in the one end of the hose 40 be drew out, fluid between every two rollers 301 b can then move. By the cooperation of the rollers 301 b and the lateral wall 201, the other end of the hose 40 is gradually diastolic so as to let the fluid in the hose 40 flow out slowly. As it can be seen, the precision peristaltic metering pump 1 is capable of increasing the smooth of delivering the fluid and qualitatively controlling the quantity of outflow fluid.
With references to FIG. 4 and FIG. 5, which illustrate a schematic exploded view of the precision peristaltic metering pump device of the present invention and a schematic assembled view of the precision peristaltic metering pump device of the present invention. As shown in FIG. 4 and FIG. 5, the precision peristaltic metering pump device 2 provided by the present invention is different than aforesaid precision peristaltic metering pump 1, and the precision peristaltic metering pump device 2 further has a flexible fastening member 60 and a holding member 70; wherein the structure features of the base 10, the case structure 20, the differential device 30, and the hose 40 are described in detail already, so there are no further descriptions hereinafter.
The flexible fastening member 60 female-connects with the hose 40. The holding member 70 clamps the flexible fastening member 60, and the flexible fastening member 60 is squeezed by the holding member 70 in order to tightly wrap around the hose 40. Thus, the hose 40 may not slip while the rollers 30 squeeze the hose 40, so that the fluid in the hose 40 can accurately and quantitatively flow to a directed direction.
The hose 40 has an inlet portion 401 and an outlet portion 402, and the inlet portion 401 and the outlet portion 402 can be at the same side of the case structure 20. The flexible fastening member 60 female-connects with the inlet portion 401 and the outlet portion 402 of the hose 40, the flexible fastening member 60 is thus squeezed by the holding member 70 in order to tightly wrap around the inlet portion 401 and the outlet portion 402. The holding member 70 can be any figure of structure to hold the flexible fastening member 60 and is demanded by any request. For the preferred embodiment, as shown in FIG. 4, the one end of the holding member 70 forms two bent arm structures 701 that are corresponding to each other, the other end of the holding member 70 forms a U-type clamping structure 702, the two ends of the U-type clamping structure 702 connects with the two bent arm structure 701 respectively in order to shape as a hair pin structure. The flexible fastening member 60 is a ringer 601. The practical assembly for the flexible fastening member 60, the hose 40 and the holding member 70 will be described in detail in the following.
With references to FIG. 5 and FIG. 6, FIG. 6 illustrates a schematic top sectional view of the precision peristaltic metering pump device of the present invention. A plurality of hose limits S are between the case structure 20 and the second member 302 of the precision peristaltic metering pump device 2. As shown in FIG. 5, there are two hose limits S between the case structure 20 and the second member 302. Thus, the inlet portion 401 of the hose 40 is first fixed to one of the hose limits S. Continuously, the hose 40 can surround the rollers 301 b so as to let the outlet portion 402 be out the other hose limit S. Then, the ringer 601 female-connects with the inlet portion 401 and the outlet portion 402 of the hose 40, and the U-type clamping structure 702 of the holding member 70 is applied to clamp the ringer 601 located between the inlet portion 401 and the outlet portion 402 from the case structure 20 toward the flexible fastening member 60. The ringer 601 is squeezed by the U-type clamping structure 702 to wrap around the hose 40. Therefore, while the rollers 301 b squeeze and release the hose 40, the inlet portion 401 and the outlet portion 402 may not slip, and the flow quantity and flow direction of the fluid in the hose 40 will not be affected so as to increase the accuracy.
There is one thing to be noted. A limit portion R is between the hose limits S. While the holding member 70 clamps the ringer 601, the bottom edge 703 of the U-type clamping structure 702 of the holding member 70 is against to the limit portion R in order to effectively prevent the movement, relative to the rollers 301 b, of the hose 40. In addition, since the one end of the holding member 70 forms two bent arm structures 701 that are corresponding to each other, and the other end of the holding member 70 forms a U-type clamping structure 702. While the holding member 70 is going to clamp the ringer 601, a force is simply applied to the two sides of the U-type clamping structure 702, the distance between the two bent arm structures 701 may be automatically larger in order to let the U-type clamping structure 702 female-connect with and clamp the ringer 601, and the inlet portion 401 and the outlet portion 402 of the hose 40 may not happen relative motions. More, because of a pre-determined width L of the ringer 601, and while the holding structure 70 is going to use the ringer 601 to wrap around the hose 40, the touching area of the ringer 601 and the hose 40 is increased due to the pre-determined width so as to let an increased static friction strengthen the bonding forces between the ringer 601 and the hose 40. On the other hand, the flow quantity of the fluid in the hose 40 may not be affected. Additionally, the hose 40 and the ringer 601 are made of silicone. Hence, the holding member 70 and the flexible fastening member 60 of the precision peristaltic metering pump device 2 are simple, easily assembled, hardly out of order, and stable.
According to aforesaid, the present invention has some advantages listed below:

1. The differential device of the precision peristaltic metering pump is able to accurately control the speed of the rollers squeezing the hose in order to approach the requirement of precision flow.
2. The differential device of the precision peristaltic metering pump is simple, cost-saving, easily assembled, hardly out of order, and stable, and the rollers can be effectively controlled.
3. The differential device of the precision peristaltic metering pump is able to accept larger power input, tooth-broken may not be happening very easily, the structure is compact, and the performance is stable as well.
4. The flexible fastening member of the precision peristaltic metering pump device is squeezed by the holding member to wrap around the hose so as to prevent that the hose slips while the rollers squeeze the hose. The holding member and the flexible fastening member of the precision peristaltic metering pump are simple, easily assembled, hardly out of order, and stable.

The descriptions illustrated supra set forth simply the preferred embodiments of the present invention; however, the characteristics of the present invention are by no means restricted thereto. All changes, alternations, or modifications conveniently considered by those skilled in the art are deemed to be encompassed within the scope of the present invention delineated by the following claims.

Claims

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.