Peristaltic Pump Roller Stop Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Peristaltic pumps often experience fluid bypass when stopped due to tolerances and geometry issues, which can lead to unintended fluid flow, posing risks in applications like blood processing where precise control is critical.
Innovation Solution
A peristaltic pump design with a rotor and two rollers that transition between disengaged, initially engaged, and fully engaged positions, using an encoder and rotor controller to ensure that at least one roller remains fully engaged when the pump stops, preventing fluid bypass by monitoring roller positions and controlling the rotor's stoppage accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pump is stopped using conventional control methods, then the pump stops operation, but fluid bypass occurs due to tolerance and geometry issues allowing unintended fluid flow
Solution Approach 1:
An encoder monitors the position of rollers on the rotor and provides feedback to the controller. The controller uses this feedback to determine when to stop the rotor such that at least one roller remains in the fully engaged position, preventing fluid bypass while maintaining reliable fluid control.
Solution Approach 2:
The system proactively positions the rollers before stopping the pump by monitoring roller positions with an encoder and controlling the rotor to stop when a roller is fully engaged. This preliminary positioning action prevents fluid bypass from occurring in the first place.
2Ease of operation
If the rotor stops without position control, then the pump stops operation, but the tubing may not be fully occluded due to tolerance accumulation
Solution Approach 1:
The encoder provides real-time feedback on roller position, enabling the controller to compensate for manufacturing tolerances in the rotor, rollers, and tubing. This feedback mechanism ensures precise occlusion despite tolerance accumulation in individual components.
Solution Approach 2:
The system changes the operational parameter of rotor position by using encoder feedback to control the stop position dynamically. Instead of fixed positioning, the rotor is controlled to stop at variable positions that ensure full occlusion, compensating for manufacturing variations.
3Reliability
If an encoder and rotor controller are added to monitor and control roller positions, then fluid bypass is prevented, but device complexity increases
Solution Approach 1:
While adding an encoder and controller increases device complexity, the feedback mechanism provides reliable fluid occlusion by monitoring roller positions and controlling the rotor stop position. The complexity is justified by the critical need for reliable fluid control in applications like blood processing.
Solution Approach 2:
The patent replaces purely mechanical positioning methods with an electromechanical system using an encoder and electronic controller. This substitution enables precise position monitoring and control, achieving reliable occlusion that cannot be obtained through mechanical tolerances alone.
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 solution effectively prevents fluid bypass during pump stoppage, ensuring that the tubing remains fully occluded, thereby maintaining process integrity and safety in applications like blood processing by ensuring that the pump stops only when the tubing is fully occluded, reducing the risk of fluid leakage.
Implementation Method 1
The encoder is located on the rotor and may monitor the position of the first and second rollers as the rotor rotates about the axis
Implementation Method 2
the first roller starts to occlude the section of tubing when in the initially engaged positon and fully occlude the section of tubing when in the fully engaged position. The second roller also rotates between a disengaged, initially engaged and a fully engaged position with respect to the section of tubing
Implementation Method 3
a rotor configured to rotate about an axis. The first roller rotates between a disengaged, initially engaged and a fully engaged position with respect to the section of tubing as the rotor rotates
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A peristaltic pump includes a rotor and first and second rollers mounted on the rotor. The first and second rollers rotate between a disengaged, initially engaged and a fully engaged position with respect to a section of tubing. The rollers begin to occlude the tubing when in the initially engaged positon and fully occlude the tubing when in the fully engaged position. The pump also includes an encoder and a rotor controller. The encoder monitors the position of the first and second rollers as the rotor rotates. The rotor controller is in electrical communication with the encoder and controls the operation of the pump and rotor. The controller stops the rotation of the rotor in response to a stop command and based upon the monitored position of the first and second rollers such that either the first or second roller remains in the fully engaged positon.