Last October, Henry had planned to go to Hawaii with his family for a vacation. The day before he left, he was informed that a customer complained about the vibration problem of his company's hydraulic power unit during low-speed operation. The boss asked Henry to solve the problem immediately. As the purchasing manager of the company, he had to cancel the annual leave. The engineer tested the hydraulic system on site and preliminarily judged that the hydraulic counterbalance valve was abnormal. The engineer disassembled the hydraulic counterbalance valve and failed to find out the reason. The hydraulic counterbalance valve was tested separately, and each parameter was up to standard. Henry began to contact the local hydraulic counterbalance valve supplier and wanted to solve it as soon as possible, but there was no reply.
Henry found the original hydraulic counterbalance valve manufacturer. The factory said that he OEM the hydraulic counterbalance valve completely according to their hydraulic counterbalance valve drawings. He also specially retested the hydraulic counterbalance valve in stock, and its parameter basis was qualified. Henry was embarrassed to face such a situation. Henry thought of AAK because we helped him solve the difficult problems of hydraulic counterbalance valves several times before.
We received Henry's email and understood that neither the original manufacturer nor the local manufacturer provided solutions. According to the working video of the pressure unit provided by Henry, our engineers recognized their preliminary judgment that the hydraulic counterbalance valve was abnormal. The function of the hydraulic counterbalance valve is to balance the "negative load force" opposite to the required movement direction, which makes the hydraulic motor easier to control. The vibration problem in the complaint is that the hydraulic counterbalance valve affects the control ability of the balance circuit to the load. This is just our first guess about the fault. The specific situation needs to be determined in combination with the actual hydraulic counterbalance valve samples.
Henry sent us the hydraulic counterbalance valve samples the next day. After our engineers disassembled it, we are 90% confident that our judgment is correct. The check valve throttling groove of their hydraulic counterbalance valve is a traditional design. According to the working condition of their pressure unit, the design of double triangular throttling groove of hydraulic counterbalance valve has a little influence on the stability of valve spool. The hydraulic counterbalance valves we shipped to a Russian customer 2 years ago also encountered similar problems. I suggest Henry redesign the structure of the hydraulic counterbalance valve. A month later, AAK sent out 10 samples of hydraulic counterbalance valves, Henry installed the equipment for commissioning, and there was no vibration problem.
AAK engineers changed the design of the check valve throttling groove of the hydraulic counterbalance valve from double triangular throttling groove to independent triangular throttling groove. The overflow area of the throttling groove, the internal fluid flow of the check valve spool and the dynamic characteristics of the balance circuit were compared and analyzed. Finally, it was determined that the triangular throttling groove had a much smaller impact on the stability of the valve spool and the system than the double triangular throttling groove.
Henry sent me photos of a happy vacation in Hawaii and thanked AAK for solving the problem professionally. His boss was very satisfied with his quick solution to the problem and specially gave him two more days off. He was very happy.
AAK hydraulic counterbalance valves, your problem today may be the road I walked yesterday. You can have a small try!
AAK HYDRAULIC VALVE (193) 2022-04-11