Patent ID: 6227714
Filing Date: 2001-05-08
Classification: F16C,G11B

Abstract:
A combination of a compound bearing assembly for a swing arm of a hard disc drive and a swinig arm mounted thereon, comprising:a compound bearing, including:a stepped shaft (1) having a large-diameter portion (1a) and a small-diameter portion (1b), said large-diameter portion (1a) having one inner raceway groove (2a) directly formed in an outer peripheral surface thereof,a distinct-member ball bearing unit (7);an elongated sleeve-like outer race ring (5) surrounding said large-diameter portion (1a) of said stepped shaft (1),said sleeve-like outer race ring (5) having one end thereof adjacent a distinct-member outer race ring (7b) of said distinct-member ball bearing unit (7);said sleeve-like outer race ring (5) having only one outer raceway groove (2c) directly formed in an inner peripheral surface thereof adjacent the other end thereof;said distinct-member outer race ring (7b) having an outer raceway groove (9b) formed in an inner peripheral surface thereof;said distinct-member outer race ring (7b) being longitudinally adjacent to and longitudinally distinct from said sleeve-like outer race ring (5);said sleeve-like outer race ring (5) being longer than said distinct-member outer race ring (7b) of said distinct-member ball bearing unit (7);a plurality of balls (4) received in said inner raceway groove (2a) directly formed in said large-diameter portion (1a) and retained in said outer raceway groove (2c) directly formed in said inner peripheral surface of said sleeve-like outer race ring (5); anda plurality of other balls (8b) received in an inner raceway groove (9a) formed in an inner race ring (7a) of said distinct-member ball bearing unit (7), said inner race ring (7a) fitted on said small-diameter portion (1b) of said stepped shaft (1), said other balls (8b) retained in said outer raceway groove (9b) formed in said distinct-member outer race ring (7b); anda swing arm of a hard disc drive mounted on said compound bearing,wherein said swing arm includes a boss (14) having a central hole (14a) formed axially therethrough,said boss being mounted within said central hole (14a) to said sleeve-like outer race ring (5) and to said distinct-member outer race ring (7b) and rotatable about said compound bearing assembly.