Single
or double piece clamp style shaft collars are used to
provide axial location on, or for, shafts. I have found
them particularly useful when trying to design shafts
and axles which require a minimum of lathe turning
operations. The collars can perform the same axial
location function as steps or shoulders machined into
the
shaft and can be used, for example, to locate unstepped
parallel shafts or axles against their supporting
bearings. The clamp style collars are removable and
position adjustable which allows adjustment of a shaft
on assembly. They are usually non marking.
I
have mainly used single piece collars which are designed
to be slid onto a parallel shaft from a free end, double
piece collars are also available which can be assembled
on more difficult to access shafts. Steel, stainless
steel, aluminium and plastic collars can be obtained.
The axial load holding capacity of collars can be
considerable, for example a Ø12 mm steel collar can have
an axial load carrying capacity in excess of 500kgf -
it should be noted that the degree to which the tightening cap screw is torqued
has a significant effect on load carrying capacity and
manufacturers will give guidance on this - so check the full
technical specifications for the collar and its assembly if heavy axial loads are
expected. For less arduous duty the tightening torque is
less critical as even modest hand tightening with a hex
key will hold the collar in position in many
applications.
Typical
applications in our designs are for locating final drive
axles and for positioning and holding steering columns.
The images show 12 and 16 mm collars on steering columns
and drive axles.