Transformer clamps can be classified according to different standards, commonly by position and structural form. By position, they are mainly divided into upper clamps and lower clamps. The upper clamps are used to clamp the upper yoke of the iron core, and the lower clamps correspond to the lower yoke. For large transformers, they are further divided into high-voltage upper clamps, high-voltage lower clamps, low-voltage upper clamps, and low-voltage lower clamps according to the arrangement of high and low voltage sides of the leads. By structural form, traditional large-capacity transformers mostly adopt a "square iron" structure, connecting the upper and lower clamps through tension screws; the new structure uses steel strips or epoxy glass ribbons to tighten the clamps on both sides along the outside of the iron yoke, and transmits force through the "pull plate" close to the surface of the iron core, which is lighter in structure and more uniform in force.
Core Function: As a rigid fixing component for transformer cores and windings, it fastens the two into an integrated unit through connectors such as bolts and pull plates, resisting electromagnetic forces and mechanical vibrations during operation to prevent loosening or displacement of components.
Structural Characteristics: Mostly adopt a frame structure formed by welding or bolt splicing of section steels like angle steel, channel steel, and steel plates. The shape matches the contours of the core and windings, with reserved bolt holes, positioning slots, and other connection interfaces. Some are designed with ventilation holes to assist in heat dissipation.
Material Selection: Mainly use high-strength steel. Ordinary transformers commonly use carbon steel such as Q235; for large or high-voltage transformers, low magnetic permeability non-magnetic steel is selected to reduce eddy current losses, and insulating pads are added to some contact parts.
Classification by Installation Position: Divided into upper clamps and lower clamps, which are respectively located at the upper and lower parts of the core and windings, forming a symmetrical fixing frame to ensure balanced overall stress.
Classification by Structural Form: Including integral type (commonly used in small transformers, with strong rigidity and integral welding) and combined type (suitable for large transformers, with multi-component splicing for easy transportation and installation).
Auxiliary Roles: In addition to fixing, it needs to be reliably grounded to avoid accumulation of static electricity or induced voltage. Meanwhile, some structures can cooperate with cooling systems (such as oil circulation in oil-immersed transformers) to optimize heat dissipation paths.
Performance Requirements: It needs to have sufficient mechanical strength (especially to withstand instantaneous impact forces during short circuits), low magnetic permeability (to reduce additional losses), and good corrosion resistance (to adapt to the operating environment).
Impact of Quality: Its design and manufacturing accuracy are directly related to the service life and safety of the transformer. Insufficient strength or poor fixing may cause increased core vibration noise, winding deformation, or even insulation breakdown and other faults.
