Fan shaft structure

1 . A fan shaft structure, comprising a fan frame, a fan blade, a rotating shaft and a driving unit, wherein:

said fan frame comprises an accommodating space, an axle seat with an accommodating groove is protruded in said accommodating space for said rotating shaft to be mounted in the accommodating groove of said axle seat and for a stator silicon steel sheet set and a circuit board of said driving unit to be mounted on the outside of said axle seat, wherein at least one bearing located at an outside of said rotating shaft is selectively made of copper or plastic material with a hardness of less than 50 HV, and is selectively cylindrical or “U”-shaped or both cylindrical and “U”-shaped;

said fan blade comprises a hub with a receiving space therein, an iron shell attached to the hub facing said receiving space for attaching a rotor magnet relative to the outside of said stator silicon steel sheet set to be mounted inside said iron shell, said axle seat with said accommodating groove mounted in the center of said accommodating space of said fan frame, the inside of said accommodating groove of said axle seat is provided with the at least one said bearing, at least an oil-containing member stacked on the at least one said bearing and located between the at least one said bearing and a bottom side of said fan blade, and at least an oil-retaining cap stacked on at least one said oil-containing member, a rotating shaft seat has one side thereof connected to the center of said fan blade and an opposite side thereof extended toward a top of said accommodating groove of said axle seat assembled on said fan frame and coupled with an end of the rotating shaft;

wherein the rotating shaft in the accommodating groove is externally mounted with a bearing bracket, the bearing bracket includes at least one isolation ring protruded toward inside the bearing bracket, and the outside of the rotating shaft is mounted with the at least one said bearing and the at least one oil-containing member.

2 . A fan shaft structure, comprising a fan frame, a fan blade, a rotating shaft and a driving unit, wherein:

said fan frame comprises an accommodating space, an axle seat with an accommodating groove is protruded in said accommodating space for said rotating shaft to be mounted in the accommodating groove of said axle seat and for a stator silicon steel sheet set and a circuit board of said driving unit to be mounted on the outside of said axle seat;

said fan blade comprises a hub with a receiving space therein, an iron shell attached to the hub facing said receiving space for attaching a rotor magnet relative to the outside of said stator silicon steel sheet set to be mounted inside said iron shell, said axle seat with said accommodating groove mounted in the center of said accommodating space of said fan frame, the inside of said accommodating groove of said axle seat is provided with at least one said bearing, at least an oil-containing member stacked on the at least one said bearing and located between the at least one said bearing and a bottom side of said fan blade, and at least an oil-retaining cap stacked on at least one said oil-containing member, a rotating shaft seat has one side thereof connected to the center of said fan blade and an opposite side thereof extended to a top of said accommodating groove of said axle seat assembled on said fan frame and coupled with an end of the rotating shaft, wherein the at least one said oil-retaining cap is provided with a shaft hole with a hole diameter smaller than the outer diameter of said rotating shaft; said rotating shaft comprises a groove and is further mounted with a retaining ring at a bottom side of at least one said oil-retaining cap;

wherein the rotating shaft in the accommodating groove is externally mounted with a bearing bracket, the bearing bracket includes at least one isolation ring protruded toward inside the bearing bracket, and the outside of the rotating shaft is mounted with the at least one said bearing and the at least one oil-containing member.

3 . The fan shaft structure as claimed in claim 1 , wherein the at least one said bearing located at the outside of said rotating shaft is a composite plastic material having a hardness below 50 HV, self-lubricating properties, friction coefficient less than 0.3, non-conductivity, and temperature resistance higher than 100 degrees C., and is selectively cylindrical or “U”-shaped or both cylindrical and “U”-shaped.

4 . A fan shaft structure, comprising a fan frame, a fan blade, a rotating shaft and a driving unit, wherein:

said fan frame comprises an accommodating space, an axle seat with an accommodating groove is protruded in said accommodating space for said rotating shaft to be mounted in the accommodating groove of said axle seat and for a stator silicon steel sheet set and a circuit board of said driving unit to be mounted on the outside of said axle seat, wherein

said fan blade comprises a hub with a receiving space therein, an iron shell attached to the hub facing said receiving space for a rotor magnet relative to the outside of said stator silicon steel sheet set to be mounted inside said iron shell, said axle seat with said accommodating groove mounted in the center of said accommodating space of said fan frame, the inside of said accommodating groove of said axle seat is provided with at least one said bearing, at least an oil-containing member stacked on the at least one said bearing and located between the at least one said bearing and a bottom side of said fan blade, and at least an oil-retaining cap stacked on at least one said oil-containing member, a rotating shaft seat has one side thereof connected to the center of said fan blade and an opposite side thereof extended to a top of said accommodating groove of said axle seat assembled on said fan frame and coupled with an end of the rotating shaft;

wherein the rotating shaft in the accommodating groove is externally mounted with a bearing bracket, the bearing bracket includes at least one isolation ring protruded toward inside the bearing bracket, and the outside of the rotating shaft is mounted with the at least one said bearing and the at least one oil-containing member.

5 . The fan shaft structure as claimed in claim 2 , wherein said oil-retaining cap is provided with said shaft hole with a hole diameter smaller than the outer diameter of said rotating shaft, and said shaft hole is set within said groove of said rotating shaft, said oil-retaining cap is inverted U-shaped.

6 . The fan shaft structure as claimed in claim 3 , wherein the composite plastic material is PTFE (polytetrafluoroethylene), or PEEK (polyetheretherketone).