Linear Peristaltic Pump with Horizontal Motor for Stability
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Solution Overview
Problem
Existing peristaltic pumps face challenges with instability during tube installation due to their curved configuration, low flow rates, and increased weight when attempting to enhance fluid flow, which complicates medical applications like intravenous infusion and wound drainage.
Innovation Solution
A rotary cam actuated linear peristaltic pump design featuring angularly offset cam lobes that traverse pistons in a wave format to occlude and push fluid through a tube, utilizing a worm drive and gear for mechanical advantage to reduce motor size and prevent backflow, allowing for higher flow rates without increasing pump weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the pump is made top heavy to increase motor power for higher flow rates, then the flow rate increases, but the pump becomes unstable and shifts during tube installation
Solution Approach 1:
The patent repositions the motor from a vertical arrangement (causing top-heaviness and instability) to a horizontal arrangement at the base of the pump. This dimensional change moves the heavy component away from the vertical center of gravity, stabilizing the pump during tube installation while maintaining the power needed for high flow rates up to 1500 mL.
2Productivity
If the motor size is enlarged to handle increased load for higher flow rates, then the flow rate increases, but the pump weight increases causing further instability
Solution Approach 1:
The motor is reconfigured from a vertical orientation to a horizontal orientation at the pump base. This dimensional repositioning allows the motor to be located away from the vertical center of gravity, reducing the moment arm that causes instability. The horizontal placement maintains motor power for high flow rates while minimizing weight-related instability during tube installation.
3Ease of operation
If the tube installation is performed with the pump hung on a stand, then the pump can be positioned for operation, but the curved configuration makes it difficult to fit locator pin and shut off valve into recesses
Solution Approach 1:
The patent inverts the traditional curved peristaltic pump configuration to a linear configuration. The pistons are arranged in a straight line rather than a curved pattern, and the platen has a flat surface instead of a curved bottom surface. This inversion simplifies the geometry, making it easier to access and install components like the locator pin and shut off valve during tube installation, while maintaining the peristaltic pumping function.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design enables easier tube installation, increased fluid flow rate up to 1500 mL, and improved pump stability, addressing the limitations of previous peristaltic pumps by using a smaller motor to achieve higher performance.
Implementation Method 1
A peristaltic pump is a positive displacement pump that moves fluid by compressing a flexible tube with one or more pistons in a sequential manner to occlude the tube and push the fluid through the tube in one direction
Implementation Method 2
the cam lobes are operative to traverse the pistons toward the extended position... the pistons are traversed to the extended position in a wave format... the piston and the platen squeeze the tube so as to occlude the tube
Implementation Method 3
The worm drive and worm gear provide a gear reduction (i.e., mechanical advantage) so that a smaller motor is capable of running the pump
Implementation Method 4
A motor and the cam shaft are in mechanical communication with each other by way of a worm drive and a worm gear
Implementation Method 5
the cams also raise lifters which provide a mechanical advantage to reduce the load required to lift or traverse the pistons to the extended position
Data Source
AI summary
A rotary cam actuated linear peristaltic pump includes a plurality of cams which actuate a plurality of pistons. The cams apply a force to the piston by way of a lifter for providing mechanical advantage so that a smaller motor may be used to rotate the cam. Each piston of a plurality of pistons is sequentially raised to the extended position to squeeze a tube so as to flow fluid through the tube.