| 摘要 |
<p>HYDRAULIC SLEEVE VALVE AND SEAL ARRANGEMENT FOR PISTON PUMP To prevent leakage of wet concrete passing from a reciprocating pump to a delivery conduit and to prevent clogging of the seal and valve means interposed between the pump outlets and the mouth of the delivery conduit, a floating sleeve is biased by pump system hydraulic pressure into solid engagement with the wear ring which in turn is held in firm sliding contact and sealed engagement with an opposing wear plate at the outlets of the pump structure. The floating sleeve is pressure sealed on opposite sides of a delivery port for pressurized hydraulic fluid to positively exclude concrete from fouling the operation of the sleeve. Concrete grout under pressure entering a void behind the sleeve applies additional pressure to the sleeve to bias the wear ring even in the event of hydraulic pressure loss. The grout within the void prevents the sleeve from ever backing away from the wear ring.</p> |
