Multi-Motor Gear Drive with Shifted Commutation for Low Torque Ripple
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multi-motor drive systems face challenges in efficiently managing torque ripple and achieving optimal efficiency due to synchronized commutation drive signals, leading to suboptimal power output and increased thermal losses.
Innovation Solution
The implementation of a multi-motor drive unit with sequentially oriented motors and shifted commutation drive signals, distributing torque ripples and optimizing each motor's commutation band to peak efficiency, thereby reducing torque ripple and enhancing overall system efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If synchronized commutation drive signals are used in multi-motor drive systems, then motor control is simplified, but torque ripple increases and efficiency decreases
Solution Approach 1:
The patent applies periodic action by implementing sequential commutation of motors at different phases within the commutation cycle. Each motor is commutated for a sub-portion of the cycle, creating a distributed periodic pattern that smooths torque delivery and reduces ripple while maintaining control simplicity
Solution Approach 2:
The patent changes the timing parameter of commutation signals for each motor, shifting them relative to one another. This parameter modification allows each motor to operate at peak efficiency during its designated sub-portion of the commutation cycle, reducing overall thermal losses while maintaining synchronized operation
2Device complexity
If synchronized commutation drive signals are used in multi-motor drive systems, then motor control is simplified, but torque ripple increases
Solution Approach 1:
The patent implements periodic action through sequential motor commutation where each motor operates during a specific sub-portion of the commutation cycle. This creates a distributed torque pattern that smooths the overall torque delivery, reducing ripple while keeping control signals synchronized and simple
Solution Approach 2:
The patent segments the commutation cycle into sub-portions, assigning each motor to a specific time window within the cycle. This segmentation distributes the torque production across time, preventing simultaneous commutation events that cause torque ripple while maintaining overall synchronization
3Power
If motors are commutated simultaneously, then power output is maximized, but efficiency decreases due to thermal losses
Solution Approach 1:
The patent uses periodic action by dividing the commutation cycle into sub-portions and assigning motors to different time windows. This maintains continuous power output through sequential operation while allowing each motor to operate at peak efficiency during its designated period, reducing thermal losses
Solution Approach 2:
The patent applies preliminary action by pre-planning the commutation sequence and timing for each motor before operation begins. Each motor is prepared and positioned to commutate at its optimal moment in the sequence, ensuring peak efficiency operation while maintaining continuous power delivery
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 significantly reduces torque ripple and improves efficiency, achieving higher power output while minimizing thermal losses and eddy current dissipation, resulting in a more effective and efficient power transmission system.
Implementation Method 1
a plurality of motors disposed around a center longitudinal axis along a radial plane and secured to the rear cover, each motor including a drive output and a pinion
Implementation Method 2
a master gear including peripheral teeth in driving engagement with the pinions
Data Source
AI summary
A multi-motor drive unit includes a rear cover and a plurality of motors disposed around a center longitudinal axis along a radial plane. A rear end of the plurality of motors is secured to the rear cover and each of the plurality of motors includes a pinion. The multi-motor drive unit includes a master gear including peripheral teeth that engage the pinion of each of the plurality of motors, a motor adapter disposed between the master gear and the plurality of motors to pilot and support the master gear and a front end of the plurality of motors, an output shaft, and a front cover to pilot and support an output bearing of the output shaft.