Variable-Ratio LC Pump Drive for Precise Wide-Range Solvent Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid chromatography pump drive systems are limited by their inability to maintain precision and resolution when operating outside their ideal flow rate and pressure ranges, often requiring large motors that compromise performance at lower speeds.
Innovation Solution
A variable output drive system with a gearbox that provides non-equal input-to-output ratios, utilizing planetary gear systems and a clutch mechanism to accommodate various flow rates and pressures, allowing a single pump to operate across different chromatography systems and techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If large motors are used to handle high end speeds and loads, then the pump can operate at high flow rates, but the precision and resolution of flow rate and pressure output suffer when run at lower speeds
Solution Approach 1:
The patent applies dynamics by making the gear ratio variable rather than fixed. The planetary gear system allows the gear ratio to be dynamically adjusted based on operating conditions, enabling the motor to operate in its optimal precision range while adapting to different flow rate requirements. This resolves the contradiction by allowing high flow rates when needed while maintaining precision when operating at lower speeds.
Solution Approach 2:
The patent changes the parameter of gear ratio from constant to variable. By adjusting the gear ratio parameter according to the desired flow rate and pressure conditions, the system can maintain motor operation within its optimal precision range across a wide operating envelope, thus resolving the contradiction between high productivity capability and measurement precision.
2Measurement precision
If drive systems are designed for very specific flow rates and pressures, then they perform accurately within the ideal range, but they are quickly de-rated when operating outside the ideal range
Solution Approach 1:
The variable gear ratio system allows the drive system to adapt dynamically to different operating conditions. By changing the gear ratio, the system can maintain accurate flow rate and pressure control across a wide range of operating conditions, rather than being limited to a narrow ideal range. This resolves the contradiction between precision within ideal range and adaptability outside ideal range.
Solution Approach 2:
The patent makes the drive system universal by enabling it to perform accurately across multiple operating conditions and applications. The variable gear ratio mechanism allows a single drive system to replace multiple specialized systems, providing both analytical and preparative chromatography capabilities with consistent precision across the entire operating range.
3Adaptability or versatility
If a single pump is used to operate across different chromatography systems, then versatility is improved, but maintaining high accuracy across all flow rates becomes difficult
Solution Approach 1:
The variable gear ratio system enables a single pump to maintain high accuracy across different chromatography systems by dynamically adjusting the gear ratio to match the specific flow rate requirements of each application. This resolves the contradiction by allowing the pump to adapt its mechanical advantage to maintain precision whether operating in analytical or preparative mode.
Solution Approach 2:
The patent achieves universality by designing a single pump system that can accurately serve multiple chromatography applications. The variable gear ratio mechanism provides the flexibility needed to maintain high accuracy across different flow rate ranges, making the pump universally applicable to both analytical and preparative chromatography systems.
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
Enables high accuracy and flexibility in flow rates from 1500 microliters per minute to less than 1 microliter per minute, supporting both preparative and analytical chromatography without the need for motor changes, enhancing operational versatility and precision.
Implementation Method 1
the variable output drive system includes a planetary gear system configured to provide a variable ratio between an input from the motor and an output delivered to at least one of the pistons
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
Disclosed is a liquid chromatography solvent pump including a motor, a first piston, a second piston, and a variable output drive system coupling the motor to at least one of the first piston and the second piston. The variable output drive system includes a gearbox configured to provide a non-equal ratio between an input from the motor and an output delivered to at least one of the first piston and the second piston. The first piston and the second piston are configured to deliver a flow of solvent in a liquid chromatography system.