Patent Summary for CN212516866U: Transformer
I. Abstract and Technical Field
The utility model provides a transformer that aims to improve energy density, reduce leakage inductance, and enhance insulation and heat dissipation compared to conventional two-slot or uniform-slot transformers.
Key Structure: The transformer comprises an iron core (1), a bobbin (2) (or winding framework), a primary winding, and a secondary winding.
Novel Feature: The bobbin adopts a three-groove winding framework with unequal winding groove widths.
Key Process/Material: The primary winding, secondary winding, and bobbin are all poured together with a casting glue (potting compound).
Benefits:
Compactness and High Energy Density: The unequal width three-slot design maximizes winding width utilization, resulting in a more compact and smaller transformer.
Improved Heat Dissipation: The casting glue is distributed all around the copper wire, which is favorable for heat dissipation.
Enhanced Insulation: Full filling by the casting glue improves the insulation properties of the copper wire, reducing the need for traditional interlayer adhesive tape.
Manufacturing Improvement: A heat dissipation groove between the wire grooves of the bobbin increases the safety distance, improves insulation, and facilitates the penetration of the casting glue.
II. Background and Description of the Invention
A. Technical Problems of Prior Art
Existing transformers, which mostly use two-slot bobbins or three-slot bobbins with equal winding widths, suffer from several drawbacks:
Large Size and Cost: Two-slot or equal-width three-slot frameworks are large, increasing the overall size and manufacturing cost of the transformer.
High Leakage Inductance: Two-groove frameworks typically result in large leakage inductance, leading to circuit radiation interference and noise in the switching power supply.
Poor Insulation and High Cost: Achieving sufficient insulation in prior art designs requires the addition of interlayer adhesive tape, reverse-folding adhesive tape, and retaining walls, which increases material cost, process complexity, and overall transformer cost.
Unstable Coupling: Winding tension and adhesive tape tension can lead to unstable winding coupling conditions and unstable leakage inductance, which negatively impacts the efficiency of the power supply.
Poor Heat Dissipation: The winding exterior is often air, which hinders heat dissipation and can cause heat concentration and the risk of burning.
B. Solution and Configuration
The invention's solution is a combination of a structural design (unequal three-slot bobbin) and a manufacturing technique (potting).
Detailed Configuration:
Winding Framework (Bobbin) (2):
Structure: A three-groove winding framework with unequal winding groove widths. The slots are specifically a primary side coil first winding groove (7), an auxiliary edge winding groove (8), and a primary side second winding groove (9).
Winding Placement: The primary winding is preferably arranged in the middle winding slot of the bobbin, and the secondary winding is arranged in the two outer winding slots of the bobbin.
Heat Dissipation/Insulation: A heat dissipation groove is provided between the wire grooves of the bobbin, which increases the safe electrical distance and facilitates the ingress and dispersion of the casting glue.
Windings:
The primary winding and secondary winding are preferably wound using Litz wires to reduce eddy current loss and copper loss, improving energy conversion efficiency.
The windings are connected by flying leads, which are preferably sleeved with an insulating sleeve.
Potting (Casting Glue):
The primary winding, secondary winding, and bobbin are all poured together by a potting compound (casting glue/sealant).
Pre-Poured Option: The primary and secondary windings can be separately pre-poured with sealant to form an annular winding rubber cake before being placed in the bobbin and sleeved onto the core post. This helps ensure the sealant is fully distributed around the copper wire, enhancing both insulation and heat dissipation.
Core (1): The center post of the iron core may be provided with an air gap.
III. Main Claims
Claim 1: A transformer, including an iron core (1), a bobbin (2), a primary winding, and a secondary winding, characterized in that:
The primary winding and the secondary winding are respectively arranged on the bobbin (2).
The bobbin (2) is arranged in the iron core (1).
The bobbin (2) adopts a three-groove winding framework with unequal winding groove widths.
Claim 2: The transformer of claim 1, where the primary winding, the secondary winding and the bobbin (2) are encapsulated by a potting compound.
Claim 3: The transformer of claim 2, where a heat dissipation groove is arranged between the wire grooves of the bobbin (2).
Claim 4: The transformer of claim 2, where the primary winding is arranged in the middle winding slot of the bobbin (2), and the secondary winding is arranged in the two outer winding slots of the bobbin (2).
Claim 6: The transformer of claim 2, where the primary winding and the secondary winding are both poured with pouring sealant around the copper wire winding in advance to enable the copper wire winding and the pouring sealant to form a ring-shaped winding rubber cake.
