Lubricating oil circulating system of special vehicle vacuum pump

The utility model relates to a lubricating oil circulating system of a special vehicle vacuum pump and belongs to the technical field of vacuum pump lubricating oil ways. According to the system, a first closed pipeline is arranged at an exhaust port of a vacuum pump, at least two oil-gas separators connected in series are arranged on the first closed pipeline, the last oil-gas separator connected in series is provided with an oil outlet and a gas outlet, and the oil outlet of the last oil-gas separator is connected with a filter through a second closed pipeline. An outlet of the filter is connected to an oil filling port of the vacuum pump through a third closed pipeline, and an air outlet of the last oil-gas separator is communicated with the atmosphere. According to the system, lubricating oil of the vacuum pump is discharged and then returns to the vacuum pump through oil-gas separation, so that the added lubricating oil in the vacuum pump is recycled, oil discharge is reduced, the use amount and cost of