| 摘要 |
PROBLEM TO BE SOLVED: To prolong the service life of a vacuum pump and to improve the durability thereof by suppressing the damages given to the vacuum pump. SOLUTION: The oil change time of a rotary pump 1117-2 being the vacuum pump, is judged by at least one of the kinematic viscosity, the total acid value and the contamination degree of the oil in the rotary pump 1117-2 and the oil is changed based on the result. For example, when one of respective conditions of >=150 mm<2> /S kinematic viscosity of the oil in the rotary pump 1117-2, >=3.5 mg/KOH total acid value and >=70 mg/100 cm<3> contamination degree is satisfied, the oil is changed.
|
