Spindle motor and manufacturing method thereof
AssigneeMinebea Co., Ltd.
InventorRikuro Obara
Life of this patent
Estimating the term…
Abstract
A spindle motor having a pivot which tip portion can easily be formed by a spherical surface having high precision, high hardness, the diameter of which can be determined as desired, the tip portion 6a of the pivot 6 is formed by cutting a steel ball used in a bearing or the like having any diameter. The pivot 6 having a spherical surface 6a is formed by fixing the pivot tip portion 6a to one side surface 6c of a substantially cylindrical shaft portion 6b. As a result, the spherical surface having a high precision, high hardness which diameter can be determined as desired can easily be formed at the tip portion 6a of the pivot 6.
Claims3
A spindle motor comprising a rotor in which a pivot having a spherical surface at a tip portion rotates in unity with a hub, a stator having a substantially cylindrical stationary shaft upright and coaxial with said pivot, said stator having a sleeve abutting to the inner surface of said shaft and said pivot inserted into said sleeve within a minute gap, a thrust plate for closing an opening on one side of said stationary shaft for supporting a spherical surface formed at the tip portion of said pivot, a fluid which is filled in said minute gap formed between said pivot and said sleeve and in a space above an upper face of said thrust plate which space communicates with said minute gap formed between said pivot and said sleeve,
- the spindle motor characterized in that said pivot half spherical steel ball having a tip portion fixed to one end of said pivot to one side surface of said shaft, wherein a hardness of the tip portion is harder than a hardness of the shaft.
A method for manufacturing a spindle motor comprising;
- a rotor in which a pivot having a spherical surface at a tip portion rotates in unity with a hub,
- a stator having a substantially cylindrical stationary shaft upright and coaxial with said pivot, said stator having a sleeve abutting to the inner surface of said shaft, said pivot inserted into said sleeve within a minute gap,
- a thrust plate for closing an opening on one side of said stationary shaft and for supporting a spherical surface formed at the tip portion of said pivot,
- a fluid which is filled in said minute gap formed between said pivot and said sleeve and in a space above an upper face of said thrust plate which space communicates with said minute gap formed between said pivot and said sleeve,
- the method comprising:
- a process for cross sectionally cutting a steel ball into said half sperical which forms a tip portion on said pivot, and
- a process of fixing one end of said pivot to one side surface of said shaft.
Dependencies are inferred from the claim text.