Abstract: A rolled iron core traction transformer, comprising an iron core (1); the iron core (1) is formed by splicing two symmetrical annealed iron-core closed single frames (1-1); each iron-core closed single frame (1-1) is formed by sequentially coiling continuous silicon steel sheets; the iron-core closed single frame (1-1) has two iron core column single bodies (1-1-1) having approximately semicircular cross sections; the iron core (1) has two iron core columns (1-2) thereon spliced by the iron core column single bodies (1-1-1) and having approximately circular cross sections; each iron core column (1-2) is sequentially provided with a low-voltage T winding (6), a low-voltage F winding (5) and a high-voltage winding (4) thereon from inside to outside; two sides of each high-voltage winding (4) are respectively provided with a first tapping area and a second tapping area; the first tapping area is provided with low-voltage side high-voltage tapping outgoing lines (16); the second lapping area is provided with high

Abstract: A rolled iron core traction transformer, comprising an iron core (1); the iron core (1) is formed by splicing two symmetrical annealed iron-core closed single frames (1-1); each iron-core closed single frame (1-1) is formed by sequentially coiling continuous silicon steel sheets; the iron-core closed single frame (1-1) has two iron core column single bodies (1-1-1) having approximately semicircular cross sections; the iron core (1) has two iron core columns (1-2) thereon spliced by the iron core column single bodies (1-1-1) and having approximately circular cross sections; each iron core column (1-2) is sequentially provided with a low-voltage T winding (6), a low-voltage F winding (5) and a high-voltage winding (4) thereon from inside to outside; two sides of each high-voltage winding (4) are respectively provided with a first tapping area and a second tapping area; the first tapping area is provided with low-voltage side high-voltage tapping outgoing lines (16); the second lapping area is provided with high

Abstract: An apparently seamless lengthened bamboo sheet is formed by lengthening a plurality of bamboo strips or blanks and assembling a plurality of lengthened bamboo strips or blanks together. A slot is formed on at least one end of the bamboo strips or blanks in direction of length, and a tenon corresponding to the slot is formed on the same end; the tenon on one bamboo strip or blank is embedded into the slot on another bamboo strip or blank. The tenon and slot are mutually matched and the two bamboo strips or blanks are engaged to each other. A method to manufacture is the apparently seamless lengthened bamboo sheet includes: forming a slot and a tenon on the end of bamboo strips or blanks; embedding a tenon at one end of one bamboo strip or blank into a slot on one end of another bamboo strip or blank; assembling and gluing a plurality of lengthened bamboo strips or blanks in direction of width or thickness; forming the bamboo sheet by a common process including pressing.

Abstract: An apparently seamless lengthened bamboo sheet is formed by lengthening a plurality of bamboo strips or blanks and assembling a plurality of lengthened bamboo strips or blanks together. A slot is formed on at least one end of the bamboo strips or blanks in direction of length, and a tenon corresponding to the slot is formed on the same end; the tenon on one bamboo strip or blank is embedded into the slot on another bamboo strip or blank. The tenon and slot are mutually matched and the two bamboo strips or blanks are engaged to each other. A method to manufacture is the apparently seamless lengthened bamboo sheet includes: forming a slot and a tenon on the end of bamboo strips or blanks; embedding a tenon at one end of one bamboo strip or blank into a slot on one end of another bamboo strip or blank; assembling and gluing a plurality of lengthened bamboo strips or blanks in direction of width or thickness; forming the bamboo sheet by a common process including pressing.