Browse Prior Art Database

Diffuser

IP.com Disclosure Number: IPCOM000041728D
Original Publication Date: 1984-Mar-01
Included in the Prior Art Database: 2005-Feb-02
Document File: 2 page(s) / 68K

Publishing Venue

IBM

Related People

Lentz, RC: AUTHOR [+2]

Abstract

Fig. 1 shows a partial section of a disk file hub and spindle assembly including a frustoconically shaped diffuser 3 that diminishes acoustic noise in an apparatus having cooling air pumped by the recording disks 4 and hub assembly 5. An acoustical noise problem may occur as a pure tone caused by the air shearing action of the rotating spindle ribs 6 passing over stationary base casting ribs 7 at the location where air enters the spindle cavity through a single hole 8 in the base casting 9. The relatively large mass of air, entering per unit of time at the single hole location, being sheared by the rib 6 interaction gives rise to a possible high energy, high acoustical noise problem. The diffuser 3, mounted between base casting 9 and spindle hub assembly 5, is designed to distribute the air through many small holes 10.

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 77% of the total text.

Page 1 of 2

Diffuser

Fig. 1 shows a partial section of a disk file hub and spindle assembly including a frustoconically shaped diffuser 3 that diminishes acoustic noise in an apparatus having cooling air pumped by the recording disks 4 and hub assembly 5. An acoustical noise problem may occur as a pure tone caused by the air shearing action of the rotating spindle ribs 6 passing over stationary base casting ribs 7 at the location where air enters the spindle cavity through a single hole 8 in the base casting 9. The relatively large mass of air, entering per unit of time at the single hole location, being sheared by the rib 6 interaction gives rise to a possible high energy, high acoustical noise problem. The diffuser 3, mounted between base casting 9 and spindle hub assembly 5, is designed to distribute the air through many small holes 10. Diffuser 3 is a smooth cone-shaped part that also provides a turbulent reducing buffer between the spindle ribs 6 and base casting ribs 7. The distribution of air through many small holes 10 reduces the mass of air sheared by any one pair of spindle ribs/diffuser hole combination. The collective low energy air shearing action of the many ribs 6/diffuser hole 10 pairs plus the buffering between spindle 5 and base casting ribs 7 provides the acoustical noise reduction. As shown in Fig. 2, the hole pattern in diffuser 3 is designed to distribute the air, somewhat evenly, over the full 360OE of spindle cavity. This, in turn, causes air to flow...