Where are Niigata vane pumps generally used?

Thread Content

Nisshinbo double-leaf pump, single-acting type: The leaves are embedded in grooves and can slide freely. When rotation occurs, the leaves are flung against the pump casing due to centrifugal force. A vane pump is a positive-displacement pump; when two adjacent leaves move to the lower position, the volume enclosed by the pump casing and the rotor is at its smallest, while it is largest when they are in the upper position. As the rotor rotates clockwise, the two adjacent leaves move from the lowest position to the highest position, which corresponds to an increase in volume; this is how oil is drawn in (from the fourth quadrant to the second quadrant)； From top to bottom, it is a process of decreasing volume; therefore, oil is pressurized (from the second to the fourth quadrant). Double-acting: When the motor drives the rotor to rotate, the vanes extend outward under the combined effect of centrifugal force and the pressure oil at the bottom of the vanes, with their tops pressing against the inner surface of the stator. The four vanes located on the four concentric arc segments form four sealed working oil chambers together with the outer surface of the rotor, the inner surface of the stator, and the two distribution plates. As the rotor rotates, these oil chambers cause changes in the volume of the sealing working oil chambers, from small to large or from large to small. Oil can be drawn in or forced out through the oil intake ports on the distribution plate (connected to the oil intake openings) or the oil discharge ports (connected to the oil discharge openings). During each rotation of the rotor, each working oil chamber undergoes two cycles of suction and compression, which is why it is called a double-acting vane pump. Since the high-pressure and low-pressure chambers are symmetrical to each other, the forces acting on the shaft are balanced, resulting in a unloaded configuration. A twin-leaf pump is composed of two single-stage leaf pumps mounted in one pump body and connected in parallel in the oil circuit. The rotors of the two vane pumps are driven to rotate by the same drive shaft, and each has its own independent oil outlet. The two pumps can have equal flow rates or unequal flow rates. The Niigata twin-leaf pump is commonly used in specialized machine tools for machining where rapid feed and normal feed rates are required; in such cases, the twin-pump system consists of a pump with a low flow rate and one with a high flow rate. During rapid feeding, both pumps supply oil simultaneously (at a lower pressure), while during normal feeding, the low-flow pump supplies oil (at a higher pressure); at the same time, the high-flow pump is unloaded in the oil circuit system. This approach allows for energy savings and reduces oil heating compared to using a single high-pressure, high-flow pump. This type of double-leaf pump is also commonly used in machine tool hydraulic systems that require two independent oil circuits that do not affect each other.