The force produced by a cylinder and the time the cylinder takes to operate are primarily dictated by the size and type of pump supplying the hydraulic oil. Many machine tools have built-in hydraulic systems that can be used to operate hydraulic workholding setups. If not, a separate pump can be used. These free-standing pumps are powered by either compressed air or electricity. (Future issues of EU will provide more details on pumps.)
|Air operated pumps |
Simple and cost-efficient. They are powered by the existing shop air supply and can be configured and adjusted easily. Air operated hydraulic pumps are best suited for low to medium duty cycles.
|Electric operated pumps |
The most versatile and are best suited for situations where automation is required. Electric pumps and corresponding controls can be completely integrated into machine tool controls, accepting and sending signals during the machining cycle. Electric pumps are recommended for high duty cycle applications. They provide the highest level of performance, durability, and automation compatibility.
If the machine tool hydraulic system does not have sufficient pressure and an external pump is not practical, a hydraulic intensifier can be used to boost the machine tool hydraulic pressure to a level suitable for the workholding cylinders. Intensifiers are simple, compact units that can be integrated directly into the fixture to provide the necessary pressure and flow.