Powered tissue resecting device

A tissue resecting device, comprising:

• an end effector assembly including a proximal hub housing and a cutting member extending distally from the proximal hub housing;
• and
• a handpiece assembly, including:
• a handle housing;
• a drive casing extending distally from the handle housing;
• a drive rotor extending through and distally from the drive casing;
• and
• a seal ring disposed about the drive rotor, the seal ring having an at-rest position and a displaced position, wherein, in the at-rest position, the seal ring is sealingly engaged between the drive casing and the drive rotor to inhibit fluid ingress into an annular space defined therebetween, and wherein, in the displaced position, the seal ring is displaced from the drive rotor to reduce friction therebetween upon rotation of the drive rotor relative to the drive casing,
• wherein, the end effector assembly is releasably engagable with the handpiece assembly and wherein, upon engagement of the end effector assembly with the handpiece assembly, a portion of the proximal hub housing is configured to urge the seal ring from the at-rest position to the displaced position, and
• wherein, with the end effector assembly engaged with the handpiece assembly, the drive rotor is coupled to the cutting member and configured to drive rotation and reciprocation of the cutting member.