干式和湿式二种空气过滤器

干式是通过一个干式滤芯，(如纸滤芯)将空气中的杂质分离出来的滤清器。轻型车(含轿车、微型车)所用的空气滤清器一般为单级。它的形状 有扁圆或椭圆及平板式。过滤材料为滤纸或非织造布。滤芯端盖有金属或聚氨脂的，外壳材料为金属或塑料。重型车由于工作环境恶劣，它的空气滤清器是多数的。级为旋流式预滤器(如叶片环、旋流管等)，用于滤除粗大颗粒杂质。主滤芯之后还有一个滤芯，其作用是在安装和更换主滤芯时，或在 主滤芯偶然损坏时防止灰尘进入发动机。芯的材料多为非织造布，也有使用滤纸的。

湿式

　　包括油浸式和油浴式两种。油浸式是通过一 个油浸过的滤芯，将空气中杂质分离出来，其滤芯材料有金属丝织物的，也有发泡材料。油浴式是将吸进的含尘空气导入油池而被除去大部分灰尘，再在带油雾的空 气向经一个由金属丝绕成的滤芯时作进一步过滤，油滴和被拦住的灰尘一起返回到油池。

Dry filter is a filter that separates impurities from the air through a dry filter element (such as paper filter element). The air filter used in light vehicles (including cars and minicars) is generally single-stage. Its shape has flat circle or ellipse and flat type. The filter material is filter paper or nonwovens. The end cover of the filter element is metal or polyurethane, and the shell material is metal or plastic. Due to the bad working environment of heavy vehicles, its air filter is the majority. The stage is a cyclone type prefilter (such as blade ring, cyclone tube, etc.) for filtering coarse particles. There is also a filter element after the main filter element, which is used to prevent dust from entering the engine when installing and replacing the main filter element, or when the main filter element is accidentally damaged. Most of the core materials are nonwovens, and some use filter paper.

Wet

Including oil immersion and oil bath. The oil immersed filter is used to separate the impurities in the air through an oil immersed filter element. The filter element materials include metal silk fabric and foaming material. The oil bath type is to introduce the inhaled dusty air into the oil pool to remove most of the dust, and then further filter the air with oil mist when passing through a metal wire wound filter element. The oil drops and the blocked dust return to the oil pool together.