Electrostatic Motor Rotor Startup Reliability
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Solution Overview
Problem
Existing electrostatic motors face challenges in reliably starting the rotor to rotate forward, especially in small-sized motors where frictional resistance needs to be minimized to increase driving force while maintaining a small rotor diameter.
Innovation Solution
The electrostatic motor employs first and second sets of fixed electrodes with specific configurations, including equal or differing numbers, out-of-phase arrangements, and concentric disposition around the rotating shaft, with a driver and controller managing drive pulses to ensure reliable startup and efficient operation, switching from high-power starting pulses to low-power pulses after stabilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the rotor diameter is reduced to minimize frictional resistance, then the motor size is reduced, but the driving force (torque) becomes insufficient
Solution Approach 1:
The rotor is segmented into multiple electret portions arranged around the rotor disc, allowing the magnetic field to be distributed across multiple segments. This segmentation enables sufficient total driving force while maintaining a compact rotor diameter, as each segment contributes to the overall torque generation.
Solution Approach 2:
The invention transitions from a single large rotor structure to multiple smaller electret portions arranged in a circular pattern around the rotor disc. This dimensional reorganization allows the motor to maintain a small overall size while accumulating sufficient driving force through the combined effect of multiple distributed electromagnetic interactions.
2Volume of moving object
If the rotor diameter is reduced to minimize frictional resistance, then the motor size is reduced, but the reliability of starting the rotor to rotate forward becomes problematic
Solution Approach 1:
The stator is equipped with multiple electrode pairs that can be selectively activated to create preliminary electromagnetic forces in different angular positions. This preliminary action capability allows the motor to reliably start rotation from any initial rotor position by pre-positioning the electromagnetic field to overcome static friction and initiate forward rotation.
Solution Approach 2:
The multiple electrode pairs are segmented around the stator, with each pair capable of independently generating electromagnetic force. This segmentation enables the motor to provide reliable starting torque from any rotor position by activating the appropriate segment of electrode pairs, ensuring consistent forward rotation startup.
3Reliability
If multiple electrode pairs are added to improve starting reliability, then the driving force is improved, but the device complexity increases
Solution Approach 1:
Multiple electrode pairs are merged into a single integrated stator structure, sharing common support elements and control circuitry. This merging approach allows the motor to achieve reliable starting performance with multiple electrode pairs while minimizing the increase in overall device complexity through shared structural and control resources.
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 configuration allows the motor to reliably start and maintain rotation with reduced frictional load, achieving sufficient torque for applications like timepieces while minimizing power consumption and size.
Implementation Method 1
an electrostatic motor comprising: a rotor (10) having charged portions (12) on an outer periphery; first and second stators (20, 30) facing the rotor (10) with first sets and second sets of fixed electrodes (21 to 24, 31 to 34)
Data Source
Figure 1
Figure 2(A)~2(B)
Figure 3
AI summary
Provided is a small-sized electrostatic motor having a rotor capable of starting reliably to rotate forward. The electrostatic motor includes a rotor rotatable around a rotating shaft, charged portions formed radially around the rotating shaft on upper and lower surfaces of the rotor, first and second stators disposed to sandwich the rotor therebetween, and first sets and second sets of fixed electrodes respectively formed radially around the rotating shaft on the surfaces of the first and second stators facing the rotor and selectively energized according to drive pulses to rotate the rotor by electrostatic force generated between the charged portions and the fixed electrodes. The average number of sets of fixed electrodes simultaneously energized in one cycle of the drive pulses out of the first sets and second sets of fixed electrodes is equal to the average of the numbers of first sets and second sets of fixed electrodes.