Browse Prior Art Database

Seal For Fluid Dynamic Bearing Spindle Motor

IP.com Disclosure Number: IPCOM000015738D
Original Publication Date: 2002-Sep-26
Included in the Prior Art Database: 2003-Jun-21
Document File: 2 page(s) / 49K

Publishing Venue

IBM

Abstract

Non operational vibration tests of the present Fluid Dynamic Bearing (FDB) spindle motor design cause oil to leak from the motor.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 73% of the total text.

Page 1 of 2

Seal For Fluid Dynamic Bearing Spindle Motor

Non operational vibration tests of the present Fluid Dynamic Bearing (FDB) spindle motor design cause oil to leak from the motor.

The figure below shows expanded views of the bearing sleeve, thrust plate and top seal. During non-op vibration, oil is splashed upward toward the top seal. For the present design (right side of Figure), there is a tight gap between the thrust plate and sleeve and oil becomes momentarily trapped in this gap. Before the oil can return to the bearing, additional oil is splashed upward as a result of the non-op vibration test. After extended vibration, oil is pushed out of the motor.

The disclosed designs eliminate the tight gap between the thrust plate and sleeve and provide a large chamber for the splashed oil to reside in until it returns to the bearing. A tight labyrinth seal with barrier film is provided to prevent leakage outside the spindle motor due to oil migration. This design requires oil to return to the bearing as a result of surface tension. The second figure shows an alternate design, in which the features of the labyrinth seal are sloped, using centrifugal force to help the oil return to the bearing.

Shaft

Top Seal

Oil

Present Design

(left side)Disclosed Design (right side)

Expanded view of thrust plate and top seal shows comparison of disclosed design vs present design.

Figure 1

Barrier Film

Thrust Plate

Sleeve

1

[This page contains 1 picture or other non-text object]

Page 2 of...