Stacked Rotor Protrusions for BSG Torque
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The torque of belt-driven starter generators (BSG) is limited due to spatial constraints and current limitations, making it difficult to increase the number of winding coils or current.
Innovation Solution
A rotor design featuring stacked rotor bodies with protrusions of varying heights, allowing for increased coil space factor and facilitated assembly, with slide edges and grooves for secure coupling and wide winding spaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the number of winding coils is increased to increase torque, then torque is improved, but spatial constraints prevent further increases in coil quantity
Solution Approach 1:
The patent transitions from a single-layer coil winding arrangement to a multi-layer stacked rotor body structure. By stacking multiple rotor bodies (first, second, and third rotor bodies) in the axial direction, the design utilizes the third dimension (axial direction) to increase total coil volume and space factor without increasing the radial or circumferential dimensions, thereby resolving the spatial constraint while maintaining increased torque capability
2Power
If the current is increased to increase torque, then torque is improved, but current limit prevents further increases
Solution Approach 1:
The patent divides the single current path into multiple parallel current paths by creating multiple independent coil windings across stacked rotor bodies. Each rotor body has its own coil windings that can carry current independently, effectively segmenting the current system to increase total current capacity without exceeding individual current limits, thereby enabling increased torque
3Volume of moving object
If multiple rotor bodies are stacked to increase coil space, then coil space factor is improved, but assembly complexity increases
Solution Approach 1:
The patent incorporates protrusions and corresponding grooves on the rotor bodies before final assembly. The protrusions extend from the outer circumferential surfaces and align with grooves on adjacent rotor bodies, creating pre-configured alignment features that guide the stacking process and ensure correct positioning, thereby simplifying the assembly of multiple rotor bodies
4Reliability
If protrusions are designed for secure coupling, then assembly reliability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent designs the protrusions with asymmetric geometry, where the protrusions extend preferentially in specific directions (first direction for first rotor body, second direction for second rotor body) rather than uniformly in all directions. This asymmetric design creates inherent mechanical guidance that tolerates broader manufacturing variations while still achieving secure coupling, thereby reducing precision requirements compared to symmetric designs
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Provided is a rotor including a first rotor body including a first protrusion protruding from an outer circumferential surface thereof and a second rotor body stacked on and coupled to the first rotor body and including a second protrusion disposed at a position different from the first protrusion with respect to a circumferential direction and protruding from an outer circumferential surface thereof, wherein a height of the first protrusion is formed to be greater than a height of the first rotor body, and a height of the second protrusion is formed to be greater than a height of the second rotor body. The rotor is formed so that coils are wound around the respective protrusions that are divided and have relatively wide winding spaces unlike a rotor integrated with protrusions around which coils are wound, thereby increasing a coil space factor and providing an effect of facilitating a winding task.