Bearings – Rotary bearing – Antifriction bearing
Reexamination Certificate
1996-10-24
2001-05-08
Footland, Lenard A. (Department: 3682)
Bearings
Rotary bearing
Antifriction bearing
C384S517000, C384S537000, C384S613000
Reexamination Certificate
active
06227714
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a compound bearing assembly for supporting a swing arm of a hard disc drive.
2. Description of the Prior Art
A prior art hard disc drive as shown in
FIG. 4
comprises a magnetic disc
11
which is driven for rotation by a motor M, and a swing arm (or head arm)
13
carrying at the end thereof a magnetic head
12
for writing data in the disc
13
at a predetermined position thereof and reading out data from the disc
13
at a given position thereof.
The swing arm
13
has a base part rotatably supported by a compound bearing assembly which uses two ball bearing units. As shown in
FIG. 6
, a prior art bearing assembly for supporting the swing arm comprises two ball bearing units A and B and a sleeve-like spacer C. These components of the bearing assembly are produced separately and supplied to the user, i.e., the hard disc drive manufacturer or the swing arm manufacturer, to be assembled on a shaft D.
In other words, with the conventional swing arm support bearing assembly, the user has to assemble the two ball bearing units on the shaft via the spacer. This poses the following problems.
(a) The shaft has to be sized in its production to the inner diameter of the inner race rings of the ball bearing units. In addition, its rigidity is subject to restrictions.
(b) The spacer should have highly accurate parallelism between and flatness of its opposite end finished surfaces.
(c) It is necessary to provide uniform contact between the opposite end surfaces of the spacer and the corresponding end surfaces of the outer race rings of the ball bearing units, thus requiring highly accurate finishing.
(d) For the above reasons, the assembling by the user cannot be easily done.
SUMMARY OF THE INVENTION
An object of the invention is to provide a compound bearing assembly, which can solve the problems discussed above and be used directly by a hard disc drive manufacturer as its user for a swing arm of a hard disc drive.
In a compound bearing assembly for a swing arm according to a first aspect of the invention, a plurality of balls are provided between an outer raceway groove formed in the inner periphery of an outer race ring and an inner raceway groove directly formed in the outer periphery of a large-diameter portion of a stepped shaft, which has the large-diameter portion and a small-diameter portion, and a plurality of other balls provided between an inner raceway groove formed in the outer periphery of an inner race ring fitted on the small-diameter portion of the stepped shaft and an outer raceway groove directly formed in the inner periphery of an end portion of a sleeve-like outer race ring.
In a compound bearing assembly for a swing arm according to a second aspect of the invention, a plurality of balls are provided between an outer raceway groove directly formed in the inner periphery of an end portion of a sleeve-like outer race ring and an inner raceway groove directly formed in the outer periphery of a large-diameter portion of a stepped shaft, which has the large-diameter portion and a small-diameter portion, and a ball bearing unit having an inner and an outer race ring and a plurality of other balls provided therebetween has its inner race ring fitted on the small-diameter portion of the stepped shaft.
In a compound bearing assembly for a swing arm according to a third aspect of the invention, a plurality of balls are provided between an inner raceway groove directly formed in the outer periphery of a large-diameter portion of a stepped shaft, which has the large-diameter portion and a small-diameter portion, and an outer raceway groove formed in the inner periphery of an outer race ring provided around the large-diameter portion, and a ball bearing unit having an inner and an outer race ring and a plurality of other balls provided therebetween has its inner race ring fitted on the small-diameter portion of the stepped shaft with a sleeve-like spacer clampedly interposed between the outer race ring of the ball bearing unit and the outer race ring provided around the large-diameter portion.
According to the first aspect of the invention, the inner race ring fitted on the small-diameter portion of the stepped shaft has an equal outer diameter to the outer diameter of the large-diameter portion of the stepped shaft, so that all the balls are the same in diameter.
According to the second and third aspects of the invention, the inner race ring of the ball bearing unit has an equal outer diameter to the outer diameter of the large-diameter portion of the stepped shaft, and the outer race ring of the ball bearing unit has equal outer and inner diameters to the outer and inner diameters, respectively, of the sleeve-like outer race ring, so that all the balls are the same in diameter.
REFERENCES:
patent: 5341569 (1994-08-01), Takamizawa
patent: 5463861 (1995-11-01), Lorenz
patent: 5547291 (1996-08-01), Miyazaki et al.
patent: 5556209 (1996-09-01), Obara et al.
patent: 0613134 (1994-08-01), None
patent: 2565017 (1985-11-01), None
Footland Lenard A.
Gopstein Israel
Minebea Kabushiki -Kaisha
LandOfFree
Compound bearing assembly for swing arm of hard disc drive does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Compound bearing assembly for swing arm of hard disc drive, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Compound bearing assembly for swing arm of hard disc drive will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2518109