Oilproof assembly, oilproof vent valve, and device with oil tank

An oilproof assembly, comprising:

• a valve body, wherein a cavity penetrating through both ends of the valve body is formed in the middle, the valve body comprises a first end and a second end, an oil passing port communicating the cavity and an exterior is arranged at the first end, and the cavity at the second end is configured to communicate with an external ventilating channel;
• a first filter element arranged in the cavity at the first end;
• a limiting part arranged in the cavity at the second end and provided with a ventilating through hole;
• and
• an elastic part arranged between the first filter element and the limiting part and configured such that after the first filter element absorbs oil to swell, at least part of oil absorbed in the first filter element is capable of being extruded by a thrust of the elastic part;
• a first pressing plate, wherein one side of the first pressing plate abuts against the first filter element, the first pressing plate is provided with a plurality of first air vents, and the first air vents are opposite to the first filter element;
• and
• a plurality of steps, wherein the steps abut against the other side of the first pressing plate, and a blank area is formed between the oil passing port and the first pressing plate through the steps.