摘要 |
A spring brake actuator (10), with a large-force compression spring (72) in a spring chamber (101) of the housing, has vent openings (102) in the housing communicating with the spring chamber (101). A gas permeable filter element (104) covers the vent openings (102), and a filter frame assembly (106) is disposed over the filter element. The filter frame assembly (106) defines tortuous air passages from the filter element (104) to atmosphere so that air entering the spring chamber from atmosphere will be substantially free of contaminants. |