Axial Air Gap Motor Bobbin Protrusion for Soft Core Winding
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Solution Overview
Problem
In axial air gap rotating electric machines, holding the core member with a wire winding jig is challenging, especially when using soft magnetic materials like amorphous metal or dust magnetic cores, leading to difficulties in ensuring a stable contact surface and increasing processing complexity and cost due to the need for strong iron cores and precise cutting processes.
Innovation Solution
The design includes a stator with pillar-shaped iron cores and a bobbin featuring a tube portion, flange portions, and a protruding portion that allows the core to be held externally, enabling efficient winding and reducing the need for strong core materials by distributing the load and minimizing the bobbin's rigidity requirements, thus allowing for higher coil density and reduced machine size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the iron core is made strong and rigid to be held by the wire winding jig, then the core member can be held stably during coil winding, but soft magnetic materials like amorphous metal and dust magnetic core cannot be used
Solution Approach 1:
The patent introduces a holding protrusion as an intermediary structure on the bobbin that directly engages with the wire winding jig, eliminating the need for the iron core to provide mechanical support. This allows soft magnetic materials to be used while maintaining stable holding during coil winding
Solution Approach 2:
The patent separates the functions of the bobbin into distinct components: the holding protrusion for mechanical support and engagement with the jig, and the main tubular body for supporting the coil. This segmentation allows the holding function to be optimized independently from the core material requirements
2Adaptability or versatility
If the iron core is made with laminated structure or compressed structure to reduce strength requirements, then soft magnetic materials can be used, but it is difficult to ensure stable contact surface with the jig
Solution Approach 1:
The holding protrusion acts as an intermediary that provides the stable contact surface for the jig, eliminating the need for the iron core to provide this function. This allows soft magnetic materials with laminated or compressed structures to be used without compromising manufacturing precision
3Strength
If the bobbin is made rigid to hold the core member from the inside, then the core can be held stably, but the bobbin size and material usage increase
Solution Approach 1:
The patent extracts the holding function from the main bobbin body and concentrates it in a small holding protrusion. This allows the majority of the bobbin to be minimized in size while maintaining the necessary holding capability through the protrusion structure
Solution Approach 2:
The bobbin can be made with thinner walls and less material since the holding protrusion provides the structural support needed for holding the core. The main body of the bobbin can be more flexible and minimal in size
Data Source
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AI summary
The present invention ensures reliability while reducing the size of an axial air gap rotating electric machine. An axial air gap rotating electric machine has: a stator (19) comprising a plurality of core members (20) arranged in a ring shape, said core members each having an iron core (21), a coil (23) wound in an iron core outer periphery direction, and a bobbin (22) disposed between the iron core and the coil; and a rotor (30) plane-facing an end surface of the iron core via an air gap in a rotating shaft radial direction. The bobbin has: a tubular portion (22a) facing the outer peripheral side surface of the iron core and shorter than the length of the iron core; flange portions (22) extending in the vicinity of both ends of the tubular portion from the outer periphery of the tubular portion toward the vertical direction outside by a predetermined length; and a projection portion (10) being on the outside surface of at least one of the flange portions and near the inner edge of the tubular portion, having an inner peripheral surface facing the end outer peripheral side surface of the inserted iron core, and further projecting in an extending direction of the tubular portion.