METHOD OF REPAIR OF POSITIVE-DISPLACEMENT HYDRAULIC DRIVE Russian patent published in 2025 - IPC B23P6/02 B22D19/10 B23K9/04 

FIELD: performing operations.

SUBSTANCE: invention relates to machine building and repair of machine parts and may be used at machine building and repair enterprises. Method comprises hardening the cylinder block soldering working surface with a tin bronze electrode in manual mode on an electric spark installation with a pulse energy of 0.045 J, pulse supply frequency 1200 Hz and processing time of 2.5 min/cm² with subsequent mechanized finishing on grinding and polishing machine. Build-up on working surfaces of pistons and slide valve of housing of rear cover by electrode from spring steel in mechanized mode on electric spark installation with pulse energy of 10 J, pulse feed frequency 45 Hz, electrode longitudinal displacement 0.16 mm/min, disc electrode rotation peripheral speed 0.018 m/s, number of passes 1. Cylinder block bushing bore and rear cover bore for slide valve are reconditioned by machining by blind adjustable diamond reamers at precision machining tool. Built-up working surfaces of pistons and rear cover housing slide valve are ground at centreless grinder to produce clearance in joints between piston and cylinder block bushing of 20-40 mcm and that of slide valve and rear cover housing bore of 10-18 mcm.

EFFECT: improving the physical and mechanical properties of applied metal coatings on the working surfaces of restored parts through the use of new electrode materials and technological modes of electric spark machining.

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