Rotary joint for LNG (Liquefied Natural Gas) filling arm

The invention discloses a rotary joint for an LNG (Liquefied Natural Gas) filling arm. The rotary joint comprises a rolling ball bearing; a left end flange and a right end flange are fixed at two ends of the rolling ball bearing respectively; the rolling ball bearing comprises an inner ring, a left outer ring and a right outer ring; a steel ball raceway which is formed between the inner ring and the left outer ring and a steel ball raceway which is formed between the inner ring and the right outer ring are formed in a staggered mode; an inner lining is arranged in the inner ring. Compared with the traditional rotary joint, the inner lining which is arranged in the rotary joint for the LNG filling arm can float laterally and accordingly the compensation on the width of a sealing ring groove is increased; an outer ring is divided into the left outer ring and the right outer ring, an annular groove which is used for performing installation limiting is formed between the left outer ring and the right outer ring, and accordingly the coaxality of the left raceway and the right raceway can be ensured; the steel ball raceway formed between the left outer ring and the inner ring and the steel ball raceway formed between the right outer ring and the inner ring are formed in a staggered mode and accordingly the capacity of the rotary joint for bearing the bending moment is increased.