Infusion Pump Motor Drive Sequence for Cogging Torque Relief
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional infusion pumps face challenges with cogging torque, which increases the size and power consumption of electromagnetic motors due to manufacturing tolerances causing misalignment of the rotor and stator, potentially rendering devices inoperable.
Innovation Solution
The motor first rotates the rotor in a counterclockwise direction for less than a full rotation to a 'windup' position, then reverses direction to overcome cogging torque, reducing peak torque requirements and allowing continuous operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electromagnetic motors are used in infusion pumps, then the motor can drive the dispenser, but the motor size and power consumption increase due to cogging torque caused by manufacturing tolerances and misalignment
Solution Approach 1:
The system performs a preliminary windup rotation in the first direction before the intended rotation direction to build kinetic energy. This preliminary action ensures the rotor has sufficient momentum to overcome cogging torque peaks during startup, allowing reliable operation with a smaller, more power-efficient motor.
Solution Approach 2:
The system converts the harmful effect of cogging torque into a beneficial mechanism by using the windup rotation to build kinetic energy that actively overcomes the magnetic attraction. The cogging torque that would normally cause misalignment issues is instead managed through controlled preliminary rotation, enabling more precise control and reduced motor size.
2Reliability
If conventional electromagnetic motors are used in infusion pumps, then the motor can drive the dispenser, but the motor size increases due to peak torque requirements from cogging torque
Solution Approach 1:
The system performs a preliminary windup rotation in the first direction before the intended rotation direction to build kinetic energy. This preliminary action ensures the rotor has sufficient momentum to overcome cogging torque peaks during startup, allowing reliable operation with a smaller, more power-efficient motor.
Solution Approach 2:
The system changes the operational parameters by introducing a two-stage rotation sequence: first rotating in the opposite direction to build kinetic energy, then reversing to the intended direction. This parameter change allows the motor to operate at lower peak torque levels, reducing motor size while maintaining reliability.
3Volume of moving object
If tighter tolerances are used in smaller pumps, then the pump can be more compact, but manufacturing complexity and cost increase
Solution Approach 1:
The system converts the harmful effect of cogging torque into a beneficial mechanism by using the windup rotation to build kinetic energy that actively overcomes the magnetic attraction. The cogging torque that would normally cause misalignment issues is instead managed through controlled preliminary rotation, enabling more precise control and reduced motor size.
Solution Approach 2:
The system changes the operational parameters by introducing a two-stage rotation sequence: first rotating in the opposite direction to build kinetic energy, then reversing to the intended direction. This parameter change allows the motor to operate at lower peak torque levels, reducing motor size while maintaining reliability.
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
This approach reduces the size and power drain of the motor while ensuring reliable operation by utilizing kinetic energy gained from the windup position to overcome magnetic attraction, making the device more efficient and reliable.
Implementation Method 1
supplying a first signal to a stator of the electromagnetic motor, thereby rotating a rotor of the electromagnetic motor
Implementation Method 2
the rotor can include a permanent magnet and the stator can include a plurality of coil windings disposed around the rotor
Data Source
AI summary
Systems and methods for driving electrical motors of medicament infusion pumps are disclosed. An infusion device for delivering a medicament to a body of a user can include a reservoir to contain medicament, a dispenser to cause medicament to be moved out of the reservoir, and a motor operably coupled to the dispenser. The motor can include a stator defining a central opening and a rotor removably disposed therein. A controller coupled to the stator is configured to (1) supply a first signal to the stator to cause the rotor to rotate in a first direction for a first rotational amount less than a full rotation; and (2) to then supply a second signal to the stator to cause the rotor to rotate in a second, opposite direction for a second rotational amount greater than the first, thereby causing medicament to be dispensed from the reservoir via the dispenser.