A tissue resecting device includes an end effector assembly including aproximal hubhousing and a cutting member extending distally from the proximal hub housing,and ahandpiece assembly. The handpiece assembly includes a handle housing, a drivecasingextending distally from the handle housing, a drive rotor extending throughand distally fromthe drive casing, and a seal ring disposed about the drive rotor. In an at-rest position, the sealring is sealingly engaged between the drive casing and the drive rotor toinhibit fluid ingressinto the annular space. Upon engagement of the end effector assembly with thehandpieceassembly, a portion of the proximal hub housing is configured to urge the sealring from theat-rest position to a displaced position wherein the seal ring is displacedfrom the drive rotorto reduce friction therebetween upon rotation of the drive rotor relative tothe drive casing.
