Support-Star Rotor Structure for Lower q-Inductance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rotors of highly dynamic servomotors with soft magnetic sheets on the rotor surface experience increased armature reaction and q-inductance, leading to reduced acceleration capability due to saturation and high q-inductance.
Innovation Solution
A rotor design comprising a support star with non-magnetic beams at the center and soft magnetic flux elements with arcs surrounding it, where permanent magnets are positioned at the radially outer end, creating a stacked structure with insulating layers and a tapering soft magnetic ring at the center of each pole.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If soft magnetic sheets are used on the rotor surface to guide magnetic flux, then magnetic field distribution is improved, but armature reaction increases causing stator saturation and reduced acceleration capability
Solution Approach 1:
The rotor is segmented into multiple material layers with alternating magnetic and non-magnetic properties. The support star with non-magnetic beams is interspersed among soft magnetic flux elements, creating a segmented structure that divides the magnetic flux paths and reduces armature reaction while maintaining effective flux guidance.
Solution Approach 2:
Different regions of the rotor are assigned different magnetic properties. The support star provides non-magnetic regions to reduce armature reaction, while the flux elements provide soft magnetic regions for flux guidance. This local differentiation allows simultaneous optimization of magnetic field distribution and acceleration capability.
2Reliability
If soft magnetic sheets are used in the rotor, then flux guidance is improved, but q-inductance increases reducing acceleration performance
Solution Approach 1:
The rotor structure is divided into discrete flux elements and non-magnetic support beams. This segmentation creates distributed flux paths that improve guidance while the non-magnetic beams interrupt continuous magnetic circuits, reducing q-inductance and enabling higher acceleration performance.
Solution Approach 2:
The non-magnetic support star acts as an intermediary element between the stator and rotor magnets. It provides structural support while preventing direct magnetic coupling that would increase q-inductance, thereby mediating between flux guidance requirements and acceleration performance.
3Stability of the object's composition
If a solid rotor structure is used for stability, then mechanical strength is improved, but inertia increases reducing acceleration capability
Solution Approach 1:
The rotor is constructed from multiple thin material layers stacked together, forming a segmented laminated structure. This provides mechanical stability through the stacked configuration while the air gaps between layers and non-magnetic regions reduce mass and inertia, enabling high acceleration capability.
Solution Approach 2:
The rotor uses a composite structure combining soft magnetic material layers with non-magnetic support elements. This composite design provides the mechanical strength and stability of a solid structure while the non-magnetic components reduce overall density and inertia for improved acceleration.
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 design reduces armature reaction and q-inductance, improving acceleration capability by enhancing synchronization and reducing inertia, resulting in higher maximum torque and steeper voltage-limit characteristics.
Implementation Method 1
one material layer has: a support star with a plurality of beams, comprising non-magnetic material, arranged in the center of the rotor
Implementation Method 2
a flux element comprising soft magnetic material, wherein the element surrounds the support star
Implementation Method 3
reduces armature reaction and q-inductance
Implementation Method 4
The rotor preferably has a plurality of permanent magnets, wherein the permanent magnets are arranged at a radially outer end of the flux element
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to a rotor (32) comprising a plurality of material layers (16), wherein a material layer (16) has: - a support star (12) with a plurality of beams (18), comprising non-magnetic material, arranged in the center of the rotor (16), - a flux element (11) comprising soft magnetic material, wherein the flux element (11) surrounds the support star, wherein a radially inner contour of the flux element has a plurality of arcs (b1, b2, b3).