Generally speaking, if the hydraulic system needs to change the flow rate, especially if the time of large flow rate is shorter than that of small flow rate, Hongyi hydraulic manufacturer suggests that we had better use double pump or variable pump. For example, the feed mechanism of the machine tool needs large flow when fast forwarding. When working, the flow rate is very small, and the difference is dozens of times or more. In order to meet the large flow required by the hydraulic cylinder during fast forwarding, a large flow pump should be selected. However, the flow required by the hydraulic cylinder during operation is very small, making most of the high-pressure hydraulic oil overflow through the overflow valve, which not only consumes power, but also heats the system. In order to solve this problem, variable vane pump can be selected. When fast forwarding, the pressure is low and the pump displacement (flow rate) is maximum. When working, the system pressure rises, the pump automatically reduces the displacement, and basically no oil overflows from the overflow valve. Double vane pump can also be used, large and small pumps supply oil at low pressure, small pumps supply oil at high pressure and low flow, large pumps supply oil at low pressure and high flow after unloading through unloading valve. Hongyi hydraulic system is also like machine tool hydraulic chuck and clamping device, or other hydraulic cylinder clamping device. Most use centralized pumping stations to supply oil, i.e. one pump is used to supply multiple machine tools. The characteristic of this system is that when clamping or loosening, the speed is expected to be very fast. It should be considered that all machine tools are clamped at the same time, so the hydraulic system needs large flow. However, once it is clamped, as long as the pressure is maintained (i.e., the clamping is tight), the time required to flow is much longer than the time the card is loaded. Therefore, the pump in this hydraulic system is useless in most cases, wasting power and causing the system to heat up. In addition, it is very disadvantageous that the pump always works at the highest working pressure. In summer, the system may have to be shut down temporarily due to high temperature. In order to solve this contradiction, the oil tank can be expanded and used to dissipate heat. However, this is a negative method. Although the system temperature can be kept stable, the power is still wasted and the hydraulic pump is worn out. A better way is to use an accumulator to store some hydraulic oil. When the system pressure reaches the highest working pressure, the hydraulic pump will unload and the pressure maintaining flow required by the system will be provided by the accumulator. When the system pressure drops to the lowest working pressure, the hydraulic pump will work again, so that the system will not generate heat, trouble will not occur easily, the oil tank is small, and the service life of the hydraulic pump will be prolonged, which is more reasonable. If you want to know more, please contact us: hydraulic vane pump.
