Minebea Company, Limited

Mineabea Co., Ltd.

Joerg Hoffman

Olaf Winterhalter

Andreas Kull

Thilo Rehm

Mathias Wildpreth

Jürgen Oelsch

Ralf Dittes

Helmut Hueneke

A hydrodynamic thrust bearing forming a part of a bearing system for a rotary bearing of spindle motors utilized to power hard disk drives. The thrust bearing includes at least one annular thrust plate and a counter bearing corresponding to the thrust plate. The thrust plate is firmly connected to a shaft rotatably supported by a radial bearing system. The shaft features an axial bore in the area of the thrust bearing, into which a fixing element is inserted. The fixing element is at least partially provided with a spherical surface. The element is inserted in such a way that the surface of the sphere projects slightly from the end of the shaft and rests on the counter bearing, at least when the motor is at a standstill. Therefore, when the motor is standing still or particularly during its start-up or shut-down phase, the spherical element (and not the bearing surface of the thrust plate) rests on the bearing surface of the cover plate. In this way, the wear and tear to the bearing surfaces and the moment of friction during start-up or shut-down of the motor are greatly reduced.

Hydrodynamic thrust bearing

A hydrodynamic thrust bearing, particularly forming a part of a bearing system for a rotary bearing of spindle motors utilized to power hard disk drives. The thrust bearing includes at least one annular thrust plate and a counter bearing corresponding to the thrust plate. The thrust plate is fixedly mounted on a shaft rotatably supported by means of a radial bearing system. The thrust plate is arranged on the shaft which is provided with an axial bore in the area where the thrust plate is to be positioned. A spherical element fixing the thrust plate is pressed into the axial bore. An outer diameter of the fixing element is greater than the inner diameter of the axial bore. This type of press connection between the thrust plate and the shaft allows comparatively thinner thrust plates to be used while the performance of the thrust bearing remains the same or improves.

A spindle motor for a hard disk drive having a stationary component with a first bearing surface, and a rotating component with a second bearing surface located in opposing relationship with the first bearing surface. The first and the second bearing surfaces form a hydrodynamic bearing. A bearing gap is formed between the first bearing surface and the second bearing surface, the bearing gap being filled with lubricating fluid. An oil-free recess is provided in the motor for placement of electromagnetic components of the motor. The stationary component is provided with a first set of seal surfaces, and the rotating component is provided with a second set of seal surfaces. The seal surfaces of the first set are located opposite the seal surfaces of the second set and form a labyrinth seal sealing the bearing gap from the oil-free motor recess.

Spindle motor and hard disk drive

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Mettlach, Germany

Joerg Hoffman