Shaft sealing assembly of handheld device, front end waterproof assembly, and host device

A front end waterproof assembly, comprising:

• a housing, defining a cavity, wherein a front end face of the housing defines a sealing hole communicated to the cavity;
• a static sealing member, received in and mated with the sealing hole, wherein the static sealing member defines a movable shaft hole communicated with the cavity;
• and
• a shaft sealing assembly, comprising:
• a center shaft;
• and
• a movable sealing assembly, comprising a fixation seat and a movable sealing member;
• wherein the fixation seat defines a sleeving hole, an inner circumferential surface of the sleeving hole defines an annular sealing slot, the sealing slot has a front wall surface and a rear wall surface opposite to the front wall surface in an axial direction;
• the movable sealing member is made of flexible material, the movable sealing member is received in the sleeving hole and extends into the sealing slot, the movable sealing member defines a fixation shaft hole which is sealed to and fixedly sleeves the center shaft, the movable sealing member is sealed to and rotatably mated to the front wall surface and the rear wall surface;
• wherein the center shaft extends through the movable shaft hole and extends out of the housing, the center shaft is sealed to and rotatably mated with the movable shaft hole;
• and
• the movable sealing assembly is received in the cavity and is disposed at a rear side of the static sealing member, the fixation seat is fixedly disposed relative to the housing;
• wherein an outer circumferential surface of the fixation seat is arranged with a positioning projection extending in the axial direction, an inner wall surface of the static sealing member defines an insertion slot mated to the positioning projection.

A shaft sealing assembly of an electric toothbrush, comprising:

• a center shaft;
• and
• a movable sealing assembly, comprising a fixation seat and a movable sealing member;
• wherein the fixation seat defines a sleeving hole, an inner circumferential surface of the sleeving hole defines an annular sealing slot, the sealing slot has a front wall surface and a rear wall surface opposite to the front wall surface in an axial direction;
• the movable sealing member is made of flexible material, the movable sealing member is received in the sleeving hole and extends into the sealing slot, the movable sealing member defines a fixation shaft hole which is sealed to and fixedly sleeves the center shaft, the movable sealing member is sealed to and rotatably mated to the front wall surface and the rear wall surface;
• wherein the fixation seat comprises a base, the base comprises a sealing cylinder and a positioning projection disposed on a front end face of the sealing cylinder,
• the positioning projection extends axially and protrudes from an outer circumferential surface of the sealing cylinder, and an inner wall surface of a static sealing member defines an insertion slot which is mated to the positioning projection.