Transformer core lamination stacking machine

01

Match lamination width and stacking concept

Tuboly-Astronic's core manufacturing leaflet shows how stacking systems are sized by lamination width and by how much of the core they build. Its conveyor stacker CSB2 handles 250 mm laminations for small distribution transformer cores; the timing-belt CSC2 handles 250, 450 or 650 mm on two levels, with or without pins; the five-position CSD(M)5 handles 250, 350 or 450 mm and stacks all three legs and both yokes from a full sequential cutting process, with automatic stack height control and compensation; and the CSA2 and CSI2 take 650 to 1,250 mm laminations. Its pick-and-place CSP uses two grippers that alternately pick sheets from the timing belt onto pallets on the left and right side, for 450 to 1,050 mm widths. [1]

The highest-automation concepts build the whole core. Tuboly-Astronic's inline E-stacking systems CSE and CSEC (450 to 1,050 mm) produce stacked 2- and 3-leg cores inline with the cutting line, with automatic stack height control, single-log production on separate pallets and an up-ending station. Its offline E-stacker CSO works independently of the cutting line for power transformer cores up to five legs, and lists detection of each sheet's position on the stack, measurement and correction of the air gap, detection of yoke-to-leg overlap and wrong sheets, and automatic change between core steps. [1]

Robot stacking is the other route. L.A.E.'s TO 25 AGILE core cutting line produces grain-oriented laminations of up to 250 mm width for step-lap distribution transformer cores from 50 to 2,500 kVA; its optional robot stacker assembles cores up to 1,500 mm long, measured tip to tip, and handles flat yokes, closed cores, E-cores or separate logs. [3]

Give the supplier the lamination width range, sheet lengths and core shapes (2-leg, 3-leg, 5-leg, E-core with open or closed top yoke), the transformer rating range, the cutting line it must work with or whether it stacks offline, how far the machine should build the core (sheet piles, legs and yokes, or the complete core on a pallet), pin or pinless stacking, maximum core height and weight, required output, floor space and controls.

02

Set the step-lap pattern, sheet thickness and output

A Westinghouse patent on step-lap cores describes the joint the stacker has to reproduce: the butt joints of each layer are offset in successive layers in the same direction to create at least three steps, and preferably at least six or seven, before the pattern repeats; it gives about 0.200 inch as a suitable step increment and notes that the best performance comes with one lamination per step, while a six-step pattern with two laminations per step gives 12 laminations per group. [4] An LSIS patent describes core laminations of silicon steel sheets with 3 to 4% silicon and a thickness of 0.23 to 0.35 mm. [5]

Tuboly-Astronic rates its CCM 450 core cutting line with the automated E-stacking system CSEC-2500 at a maximum of 40 stacked sheets per minute; the E-stacker has five independent grippers (two yokes, two side legs and one centre leg), two automatically positioned overhead stacking pins, and two stacking pallets with one up-ending station as standard. [2]

Editorial calculation: 40 sheets per minute is 40 × 60 = 2,400 sheets per hour. Ignoring the stacking factor, 100 mm of core build needs about 100 ÷ 0.23 ≈ 435 sheets of 0.23 mm steel or 100 ÷ 0.35 ≈ 286 sheets of 0.35 mm steel, about 10.9 or 7.1 minutes at that rate; the step increment of 0.200 inch is 0.200 × 25.4 ≈ 5.08 mm. [2] [5] [4]

03

EI lamination stacking and inserting machines for small transformers

The reviewed listing covers EI lamination stacking and inserting machines for small transformers, which push E and I laminations into wound bobbins, rather than stackers for distribution or power transformer cores; ask which core sizes and lamination types each machine handles.

04

Cutting-line interface, timing belts, grippers, stacking pins and height control

The gripper row separates the concepts: Tuboly-Astronic's CSEC-2500 E-stacker uses five independent grippers for two yokes, two side legs and the centre leg, while L.A.E. offers a robot stacker on its cutting line. [2] [3]

05

Lamination width, sheet thickness, step-lap pattern and sheets per minute for a stacker quotation

Only four rows carry a published figure — width, thickness, step-lap and the 40 sheets per minute of one line; stack height, accuracy, power and footprint have to come from the bidder's offer. [1] [2]

06

Send the core designs and cutting line together

Paste it into your enquiry below or into an email to a maker, then replace every bracket.

Cores: [legs; step-lap steps; kVA range]
Laminations: [width; length; thickness]
Concept: [inline; offline; robot; E-stacking]
Output: [sheets/min; cores per shift]
Stacking: [pins or pinless; max height; weight]
Site: [floor space; power; air]
Quantity: [machines]

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