KomDrive facing heads with maximum speeds
High Quality Balance
HQB is the synonym for a technology developed by the KOMET GROUP for adjusting imbalance in flat action
slides. This technology has already been used to achieve speeds which, in high-precision and high-speed
applications, effectively doubles the possible fields of application.
Facing slide tools are
mainly used in special
purpose machines, such as
automatic rotary indexing
machines
and
transfer
lines for series production,
and in combination with
KOMET KomTronic® U-axes
even in machining centres.
Thanks to the High Quality
Balance Technology from
the KOMET GROUP used
in KomDrive facing heads,
speeds have already been
achieved which, in highprecision and high-speed
applications,
effectively
doubles the possible fields
of application.
Facing slides are tools that make
flexible
contour
machining
possible through radial cutting
edge adjustment. Their field
of application is mainly special
purpose
machines,
such
as
automatic
rotary
indexing
machines and transfer lines
for
series
production,
as
well as in combination with
KOMET KomTronic® U-axes even
in machining centres. Adjusting
the cutting edges however,
involves adjusting the weights in
the tool head, which in general
causes imbalances. Round slides
with eccentric adjustment, as
usually found on the market, have
good balance properties because
of their kinematics. Disadvantage:
All process strength must be
absorbed by the drive chain. In
addition, a change in the cutting
edge positions changes the cutting
parameters, such as clearance and
rake angle, and as a consequence
the stroke must be restricted. If
you wish to use the NC technology
to influence the chip control
characteristics, then it is extremely
difficult to calculate the position
of the cutting edge.
Up until now, in conventional
flat action facing heads, balance
compensation has only functioned
statically
via
single-plane
balance compensation, which is
accomplished through a working
slide and one or more adjusting
slides
rotating
in
opposite
directions. This solution however
causes wobble and moreover the
required drive power is doubled
by the counterrotating slides.
With a long tradition
At KOMET® there is a long tradition in
the development and manufacture of
these types of tools, which is reflected
in the KomDrive family of products
with its comprehensive standard
catalogue range. A common feature
is that all sliders are driven via large
profile, diagonally cut gearing with a
maximum overlay factor. Facing head
lift can be controlled by positive stops.
Sliding parts are made of nitriding
steels nitrided over a long period to
achieve good geometric precision
with increased surface hardness
and good sliding properties. The
higher technical standard is based
on many years of experience, careful
development, design and precise
production. The individual components
are ground to fit each other and a
special treatment of the moving parts
produces favourable friction pairings.
With a maximum backlash of 5 to 15
(10) µm - depending on the product
range - the foundation has been laid
for machining complex contours with
the highest precision. Another feature
of the KomDrive facing slides is the
compact design of the slides and their
integral design, providing high cutting
efficiency without loss of precision and
service life.
Dynamic balance compensation
With the new HQB technology, the
balancing weights have been placed in
front of the slide in one plane close to
the centre of gravity for tool and slide.
Thus, by using balancing weights in one
plane, it is possible to achieve a close to
multi-plane balance, which, due to the
The radial cutting edge adjustment of
the KOMET KomTronic® -U-axes makes
flexible contour machining possible.
design, can be realised irrespective of
the stroke. In addition, the centrifugal
forces are converted into reaction
forces at coupling points so that the
centrifugal forces of the compensator
and the slide tool system in the drive
chain do not simply add up. The result
is a drive torque which is largely
separated from the centrifugal force
formula. Another not inconsiderable
factor for the smooth running of these
facing heads is their reduced overall
length; approximately 30 to 40 %,
depending on the overall size, which in
turn means reduced weight.
In practice, when used in KOMET® flataction facing heads, HQB technology
means a considerable reduction in
wobble; that is the rotational bending
moment. Depending on the snapon tool, this can be as much as 50 to
90%, whereby even 100% and thus
absolutely perfectly balanced systems
were able to be realised. The clearest
improvement was apparent in the
significantly
improved
machining
parameters for the ‚dynamic‘ balance
compensation, i.e. the rotational speeds
achievable. Currently, conventional
values are being doubled. Machineside conditions, above all the available
drive power, actually only have a
limited effect. “To drive the rotational
speeds even higher in future, the
design of individual components in
the tool heads, as regards their tensile
strengths, such as the bearing strengths
in the required size, must be developed
and engineered further“, adds Dr.-Ing.
Jürgen Fronius, responsible for the
mechatronic business unit at KOMET®.
KomDrive facing heads with HQB
technology are being successfully
used in high-speed and high-precision
applications such as in machining
journals or in boring con rods. They are
at least as good as facing slide tools
with eccentric adjustment, and may
even be superior.
With the new HQB technology, the
balancing weights have been placed in
front of the slide on a plane close to
the centre of gravity for tool and slide.
With its brands KOMET®, DIHART® and
JEL®, the KOMET GROUP is a leading
global manufacturer of precision tools
for bore machining, reaming and
threading. The group has been at the
forefront of innovation in the sector
for over 90 years - a tradition that
began with the early indexable insert
borers and continues today with their
mechatronic tool systems. The company
currently employs more than 1,600 staff
in its 20 subsidiaries and is represented
in around 50 countries.