In air-over-oil systems, compressed becomes the driving force for hydraulic circuits. An alternative to air/oil circuits is an air-powered intensifier. These devices drive a reciprocating pump, which is essentially two cylinders mounted end to end with a common rod.
The rod of a large-bore air cylinder transmits force to a small-bore hydraulic cylinder through its rod. The force delivered by the air cylinder is a function of pressure times net piston area. This same force is applied by the common rod to the much smaller piston of the hydraulics cylinder. Therefore, output pressure of the hydraulic cylinder is force-divided by net piston area. Therefore, the intensifier converts higher-flow, lower-pressure pneumatic power into lower-flow, higher-pressure hydraulic power.
Enerpac, Menomonee Falls, Wis., recently introduced its DuroTech line of air-driven hydraulic power units (intensifiers) for high-cycle industrial applications. Douglas Lacina, Workholding Commercial and Engineering Leader, explains: “Shop air is connected to the built-in pressure regulator where the operator can adjust the air pressure, in turn setting the maximum hydraulic oil pressure. The air is ported through a built-in air shut-off valve to the air pump. With the air shut-off valve open, the pump automatically turns on and off to obtain and maintain the selected hydraulic pressure.”
DuroTech pumps do not require lubricated air. They run cool and operate at noise levels of 75 dBA or lower. “One key feature to this product is the reciprocating, dual ram piston pump,” adds Lacina. “Every time the piston strokes, it creates flow, so it reciprocates less than single-ram systems do, which translates to more flow and longer life.”
The intensifiers feature a four-station DO3 manifold with cover plates for unused sections, fluid reservoir with sight glass, built in air pressure regulator, filter, and pressure gauge. DuroTech pumps come in three models, which produce maximum hydraulic flow from 612 to 252 in.3/min, max hydraulic pressure from 1,595 to 4,785 psi, and require 24 scfm maximum air flow.
Read more: Get Hydraulic Power from Compressed Air