Pleated seal passing shaft through casing and permitting turning through limited angle, comprises longitudinally-pleated, stainless steel, cylindrical tube

摘要

The seal is a longitudinally-pleated (1), stainless steel, cylindrical tube (2). The pleats taper-off toward the ends of the tube. One end is connected to the shaft, making a seal with it. The other end is connected to the casing, forming a seal. Along the cross sectional circumference, the pleats (3) have a mean radius rm. The pleat folds are curved. Inner and outer curves lie on mean pitch radii of ri (inner radius) and ra (outer radius), with ri less than rm and rm less than ra. The following inequalities are satisfied: 1.3 = rab/rm = 0.07, and 0.65 = rib/rab. The outer and inner curves describe an angle exceeding 180[deg]. Further inequalities specify suitable curve radii.