The invention concerns a roller bearing equipped with rollers held
between an inner and an outer race of the bearing and kept separate from one another
by a bearing cage which is formed by an annular component consisting of one or
more parts in which, along the circumference and at equal distances from one another,
partially or fully enclosed openings have been formed which each contain a roller.
A similar roller bearing is generally known, e.g., from the American
patent no. 3,938,866. In the known roller bearings the bearing cage - though it
does not assume any of the bearing load - is of essential importance for keeping
the rollers in the bearing separate from each other and at equal distances, so
that there will not be any contact among them.
In the known roller bearings the bearing cage is usually made in
a pressing process from metal plate such as sheet metal or sheet brass.
In the known roller bearings the friction between the rollers and
the bearing cage constitutes a serious problem which may lead - especially at high
speeds - to noise, excessive wear and tear and surface damage to the rollers.
The objective of the invention is to create a roller bearing of the
kind mentioned at the beginning whereby the aforementioned disadvantages are avoided
and whereby, in addition, the friction between the rollers and the bearing cage
is reduced to a minimum.
The objective is achieved in accordance with the invention by coating
the walls of the openings in the bearing cage entirely or partially with rubber.
On account of the porous properties of rubber, a lubricating film
is generated between the bearing cage and the rollers which is 10 to 100 times
thicker than in the known or synthetic bearing cage, leading to full hydrodynamic
lubrication. In addition, the thickness of the lubricating film will be barely
affected by locally higher contact pressures between the rollers and the bearing
According to the invention it is also preferable for the size of
the rubber-coated openings to be smaller than the size of the rollers to such a
degree that the rubber coating around the mounted rollers will be elastically deformed.
As a result, there is no need for the manufacturing tolerances of
the bearing cage material and of the rubber coating to be particularly accurate,
because any deviation in size or any error in shape will be compensated by the
elastic deformation of the rubber coating. Furthermore, the elasticity of the
rubber coating makes it possible to mount the rollers with relatively little pressure
through the narrower slots for insertion into the openings of the bearing cage,
thus preventing damage to the rollers. Moreover, a similar roller bearing will
run very quietly because there is no play between the rollers and the openings
of the bearing cage, and also on account of the damping properties of the rubber
It should be pointed out that it is generally known, among others
from the American patent mentioned above, i.e., no. 3,938,866, that in bearing
cages of the so-called snap type the openings through which the rollers are inserted
into the bearing cage are slightly smaller than the rollers themselves. Consequently,
the insertion of the rollers will occur under a certain pressure whereby the openings
are elastically deformed and surface damage occurs to the rollers. In addition,
the openings in the bearing cage which enclose the mounted rollers are designed
to be larger than the rollers so that there will be a certain amount of play between
the rollers and the openings and there will be no question of a certain pre-tension
of the cage with regard to the rollers.
According to a further elaboration of the invention the thickness
of the rubber coating is preferably 0.5 to 0.05 times the thickness of the bearing
cage material. This thickness has proved sufficient for the absorption of major
forces between the rollers and the bearing cage without damaging the rubber coating
or causing it to tear away from the cage.
For heavy-duty industrial applications the rubber coating can be
further reinforced with a mesh, fabric or strong fibers.
The invention is further explained with the help of the drawings
in which two forms of execution of a roller bearing according to the invention
- Figure 1 shows a perspective view of the roller bearing according to the invention.
- Figure 2 shows a perspective view of another form of execution of a roller
As shown in the figures, the roller bearings consists of a number
of rollers 1, 2 which are held between an inner race 3, 4 and an outer race 5,
6 of the bearing and are kept separate from one another by a bearing cage 7, 8.
The bearing cage consists of an annular component which is equipped,along its circumference
and at equal distances from one another, with openings 9, respectively 10, which
enclose partially the rollers 1, 2.
Figure 1 shows a bearing cage 7 of the so-called window type which
finds application, for example, in roller bearings. In this case the openings 9
The bearing cage 8 in Figure 2 is equipped with round openings 10
which are common, for example, in ball bearings. In this case the bearing cage
consists of two parts which are rivetted together.
The walls 11, 12 of, respectively, openings 9 and 10 are coated with
a rubber coating 13, respectively 14.
This coating can be reinforced with a mesh, fabric or strong fibers.
It will be obvious that the invention is not limited to the examples
of execution described above which, within the scope of the invention, can undergo