US Patent 7753167 Silencer

A silencer includes a cylindrical member held between a body connected to an exhaust side of a fluid pressure device and a disk-shaped retaining member. A net-shaped sound absorber is disposed around an outer circumference of the cylindrical member. A pressure fluid flows from the body into the interior of the cylindrical member and is discharged toward the sound absorber through a plurality of first through fifth exhaust holes formed in the cylindrical member. Accordingly, dust in the pressure fluid is removed by the sound absorber, which is formed of a plurality of stacked filters, and further, the pressure fluid is discharged to the outside after exhaust noises have been absorbed by the sound absorber.