| 摘要 |
FIELD: devices for transmission of reciprocating and rotary motion. SUBSTANCE: hydraulic cylinder has housing, hollow rod located inside cylinder for performing reciprocating and rotary motion and provided with piston mounted in its lower portion; said piston forms under-piston and above-piston cavities. Hydraulic cylinder is also provided with bypass pipe located in rod for forming circular and axial passages for delivery of working fluid under pressure; axial passage is connected to under-piston cavity and circular passage is connected to above-piston cavity; wall of housing is provided with bypass passage having valve for communicating the above-piston cavity of housing with under-piston cavity when piston is in lower or intermediate position; on side of upper end, rod is sealed relative to housing by means of sealing unit including sleeve with flange secured in housing by means of bolted joint and the following components located in circular clearance between rod and inner surface of sleeve: bearing bush, multi-row seal, pressure bush and pressure nut; sleeve has cylindrical section above flange which is provided with internal thread for pressure nut; height of pressure bush is no less than height of multi-row seal; height of multi-row seal ranges from 0.50 to 1.0 of diameter of rod and inner diameter of sleeve ranges from 1.2 to 1.5 of diameter of rod at point of mounting of seal. EFFECT: enhanced reliability. 3 cl, 1 dwg
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