In general, a trochoid pump is a representative displacement pump in which the flow rate is in proportion to the rotating speed of a motor.
The trochoid pump is composed of a rotor connected to a driving shaft of a motor to transfer a rotating force, and an idler coupled to the rotor to be rotated by driving of the rotor. In the trochoid pump, the rotor and the idler are eccentrically provided with a predetermined gap between them to move liquids
Korean Registered Patent No. 10-0964517 discloses “oil pump rotor”. This patent relates to an oil pump having a trochoid screw thread, which is provided with an inner rotor having outer teeth formed thereon and an outer rotor having inner teeth formed thereon to be engaged with the outer teeth of the inner rotor.
FIG. 1 illustrates a trochoid pump in the related art. The trochoid pump has an external appearance that is similar to that of a gear pump, and is manufactured using the characteristics of a geometric trochoid curve. Unlike the gear pump, the number of inner gear teeth of a rotor is set to be different from the number of outer gear teeth of an idler essentially by one, and the inner gear teeth of the rotor that come in contact with the outer gear teeth of the idler are engaged with the outer gear teeth of the idler while pushing and rotating the outer gear teeth of the idler. Accordingly, the volume between the inner gear teeth of the rotor and the outer gear teeth of the idler is changed to repeat charging and discharging of the transferred liquids.
As illustrated in FIG. 1, a trochoid pump is disclosed, in which the number of outer gear teeth of the idler is 9, and the number of inner gear teeth of the rotor is 8.
On the other hand, the trochoid pump in the related art has the problems that it is required to increase its size and weight in order to transfer the high-viscosity liquids that are gradually increased under high pressure, and thus a large-capacity motor for driving the pump is required to lower the efficiency.
Accordingly, there has keenly been a need for a high-efficiency pump that is miniaturized and light-weighted to transfer high-viscosity liquids using a small-capacity motor.