US 11,835,047 B2
Pump apparatus
Hiroyuki Kawasaki, Tokyo (JP); Takayuki Miyamoto, Tokyo (JP); Miwa Hidekura, Tokyo (JP); Hoechun Kim, Tokyo (JP); Satoshi Yamazaki, Tokyo (JP); and Xinshuai Fan, Tokyo (JP)
Assigned to Ebara Corporation, Tokyo (JP)
Appl. No. 17/635,082
Filed by Ebara Corporation, Tokyo (JP)
PCT Filed Jun. 10, 2020, PCT No. PCT/JP2020/022884
§ 371(c)(1), (2) Date Mar. 18, 2022,
PCT Pub. No. WO2021/039025, PCT Pub. Date Mar. 4, 2021.
Claims priority of application No. 2019-155673 (JP), filed on Aug. 28, 2019.
Prior Publication US 2022/0290675 A1, Sep. 15, 2022
Int. Cl. F04D 15/00 (2006.01); F04D 1/00 (2006.01); F04D 13/06 (2006.01); F04D 29/22 (2006.01); F04D 1/06 (2006.01); F04B 49/06 (2006.01); F04B 49/20 (2006.01); F04D 27/02 (2006.01); F04D 25/06 (2006.01)
CPC F04D 15/0066 (2013.01) [F04B 49/065 (2013.01); F04B 49/20 (2013.01); F04D 1/00 (2013.01); F04D 1/06 (2013.01); F04D 13/06 (2013.01); F04D 15/00 (2013.01); F04D 25/06 (2013.01); F04D 27/0261 (2013.01); F04D 29/22 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A pump apparatus comprising:
a pump having an impeller;
an electric motor configured to rotate the impeller; and
an inverter configured to drive the electric motor at variable speed,
wherein the impeller has a non-limit load characteristic in a predetermined discharge flow-rate range, and
the inverter is configured to drive the electric motor at a preset target operating point with a rotation speed higher than a rotation speed corresponding to a power frequency of a commercial power source, wherein the inverter is configured to drive the electric motor at a first rotation speed when a discharge flow rate of a liquid from the pump is lower than a preset flow rate, and to drive the electric motor at a second rotation speed when the discharge flow rate is higher than the preset flow rate, the second rotation speed is lower than the first rotation speed, and the preset flow rate is in the discharge flow-rate range.