Page 17 - The Tribology Handbook

AI Selection of bearing type and form

Examples of forms of bearing suitable for continuous movement
Examples of arrangements which Examples of arrangements which
Constraint applied to the allow movment onlv withit! this allow this movement but also haue of
ofthe Other
movement constraint other degrees offreedom freedom
About a point Gimbals Ball on a recessed plate Ball must be forced into contact
with the plate

~
About a line Journal bearing with double Journal bearing Simple journal bearing allows
thrust location free axial movement as well

Double conical bearing Screw and nut Gives some related axial move-
ment as well

Ball joint or spherical roller Allows some angular freedom
bearing to the line of rotation

~
Along a line Crane wheel restrained be- Railway or crane wheel on a These arrangements need to
tween two rails track be loaded into contact. This
is usually done by gravity.
Wheels on a single rail or
cable need restraint to pre-
vent rotation about the track
member
Pulley wheel on a cable

Hovercraft or hoverpad on a
track

~ ~~ ~ ~
In a plane (rotation) Double thrust bearing Single thrust bearing Single thrust bearing must be
loaded into contact

In a plane (translation) Hovercraft or hoverpad Needs to be loaded into contact
usually by gravity

AI .2