Design, Implementation and Evaluation of a Pump-Controlled Circuit for Single Rod Actuators

• Main Authors: Ahmed Imam, Moosa Rafiq, Ehsan Jalayeri, Nariman Sepehri
• Format: Article
• Language: English
• Published: MDPI AG 2017-02-01
• Series: Actuators
• Subjects: pump-controlled actuation; single rod actuator; counterbalance valve; efficiency
• Online Access: http://www.mdpi.com/2076-0825/6/1/10

Pump-controlled hydraulic circuits are more efficient than valve-controlled circuits, as they eliminate the energy losses due to flow throttling in valves and require less cooling effort. Presently existing pump-controlled solutions for single rod cylinders encounter an undesirable performance during certain operating conditions. This paper investigates the performance issues in common pump-controlled circuits for the single rod actuators. Detailed analysis is conducted that identifies these regions in a load-velocity plane and the factors affecting them. The findings are validated by experimental results. A new design is then proposed that employs a limited throttling valve alongside two pilot operated check valves for differential flow compensation to improve the performance. The valve is of the flow control type and is chosen to have a throttling effect over critical regions; it has the least throttling over other operating regions, thus maintaining efficiency. Experimental work demonstrates improved performance in a full operating range of the actuator as compared to a circuit that uses only the pilot-operated check valves. This circuit is energy efficient and capable of recuperating energy.