US 11,988,217 B2
Oil feed type air compressor
Shigeyuki Yorikane, Tokyo (JP); Kenji Morita, Tokyo (JP); and Yuta Kajie, Tokyo (JP)
Assigned to Hitachi Industrial Equipment Systems Co., Ltd., Tokyo (JP)
Appl. No. 18/022,635
Filed by Hitachi Industrial Equipment Systems Co., Ltd., Tokyo (JP)
PCT Filed Aug. 16, 2021, PCT No. PCT/JP2021/029876
§ 371(c)(1), (2) Date Feb. 22, 2023,
PCT Pub. No. WO2022/044863, PCT Pub. Date Mar. 3, 2022.
Claims priority of application No. 2020-141020 (JP), filed on Aug. 24, 2020.
Prior Publication US 2023/0358248 A1, Nov. 9, 2023
Int. Cl. F04D 29/063 (2006.01); F04D 27/00 (2006.01); F16N 29/00 (2006.01)
CPC F04D 29/063 (2013.01) [F04D 27/001 (2013.01); F04D 27/009 (2013.01); F16N 29/00 (2013.01); F16N 2210/16 (2013.01); F16N 2250/04 (2013.01); F16N 2250/08 (2013.01); F16N 2270/50 (2013.01)] 4 Claims
OG exemplary drawing
 
1. An oil feed type air compressor comprising:
a compressor main body that compresses air while injecting oil into a compression chamber;
a separator that separates the oil from compressed air discharged from the compressor main body; and
an oil feeding system that feeds the oil separated by the separator into the compression chamber of the compressor main body, wherein
the oil feeding system includes an oil cooler that cools the oil, a bypass pipe that bypasses the oil cooler, and a temperature control valve that adjusts a diversion ratio for the oil cooler and a diversion ratio for the bypass pipe according to a temperature of the oil, and
the oil feed type air compressor further includes
a first pressure sensor that is located in the oil feeding system and senses a pressure of the oil,
a second pressure sensor that is located on a downstream side of the first pressure sensor in the oil feeding system and senses a pressure of the oil,
a temperature sensor that senses a temperature of the air on a discharge side or an intake side of the compressor main body, and
a controller that computes, when it is estimated that the diversion ratio for the oil cooler is 100% and the diversion ratio for the bypass pipe is 0% from the temperature sensed by the temperature sensor exceeding a predetermined value, a difference between the pressure sensed by the first pressure sensor and the pressure sensed by the second pressure sensor and determines a deterioration state of the oil in reference to the difference.