METHOD OF REPAIRING HYDRAULIC CYLINDERS Russian patent published in 2013 - IPC B23P6/00 B23H9/00 C23C28/00 

FIELD: process engineering.

SUBSTANCE: invention relates to reconditioning and repairing the assembly parts and parts. Proposed method comprises boring cylinder body inner surface, honing it, hardening the piston outer working surface by electric arc by molybdenum electrode, straightening bent rod at press, boring the worn-out hole in cylinder front cover, press-fitting of bronze or cast iron sleeve therein and reaming, reconditioning the rod by electric contact welding of strip via intermediate layer to finish reconditioned surface to required allowance in rod-cylinder front cover joint, broaching and reaming of worn-out holes of rod yokes and cylinder rear cover ears to repair size, fitting the sleeves therein and finishing to rated size. Rod surface defects are eliminated by application of metal coating by electrode from copper-bearing or cermet hard alloys by electric spark processing at pulse of 0.045-.029 J for 1.5-2.5 min/cm² and the layer of metal coating by cold gas-dynamic spraying at air pressure of 0.4-0.7 MPa and with powder feed at the rate of 0.2-0.4 g/s and subsequent grinding and polishing.

EFFECT: efficient reconditioning.