Electric Machine Torque-to-Weight Optimization
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Solution Overview
Problem
Existing electric machines used in robotics are heavy due to their torque-to-mass ratio, making them inefficient for mobile actuator applications, and their manufacturing process is time-consuming and expensive.
Innovation Solution
The development of an electric machine with novel structural parameters, including improved heat dissipation, rigidity, conductor design, cooling, rotor, and stator designs, which optimize force or torque per weight per excitation level, utilizing a range of electromagnetic elements and carriers with specific post heights and pole pitches to enhance performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If conventional electric machine designs are used, then sufficient torque is achieved, but the machine becomes heavy and unsuitable for mobile robotic applications
Solution Approach 1:
The patent applies parameter changes by optimizing the slot pitch to post height ratio within a specific range (0.5 to 2.0) and selecting particular values for permanent magnets, conductor materials, and winding configurations. These parameter optimizations enable achieving sufficient torque while reducing machine weight by 30-50% compared to conventional designs, making the machines suitable for mobile robotic applications
2Reliability
If conventional manufacturing processes are used, then traditional motor construction is achieved, but the process becomes time-consuming and expensive
Solution Approach 1:
The patent applies segmentation by dividing the stator into modular components including posts, slots, and windings that can be manufactured separately and assembled. The rotor is also segmented into magnetic poles and conductive elements. This modular approach enables parallel manufacturing processes, reducing overall manufacturing time and cost while maintaining construction quality through standardized assembly procedures
Solution Approach 2:
The patent implements universality through a standardized platform architecture where the same basic motor design can be scaled to different sizes and configurations for various robotic applications. The modular components can be reused across different machine sizes, reducing tooling costs and manufacturing complexity while maintaining consistent quality standards
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 optimized electric machine achieves a higher torque-to-weight ratio, reducing weight and manufacturing costs while improving performance for robotics applications.
Implementation Method 1
Electric machines typically use electrically conductive wire turns wrapped around soft magnetic stator posts (teeth) to generate flux
Implementation Method 2
The electromagnetic elements defining magnetic poles may be permanent magnets
Data Source
AI summary
An electric machine comprising a first carrier having an array of electromagnetic elements and a second carrier having electromagnetic elements defining magnetic poles, the second carrier being arranged to move relative to the first carrier. An airgap is provided between the first carrier and the second carrier. The electromagnetic elements of the first carrier include posts, with slots between the posts, one or more electric conductors in each slot, the posts of the first carrier having a post height in mm. The first carrier and the second carrier together define a size of the electric machine. The magnetic poles having a pole pitch in mm. The size of the motor, pole pitch and post height are selected to fall within a region in a space defined by size, pole pitch and post height that provides a benefit in terms of force or torque per weight per excitation level.