Worm gearboxes are
mainly used for large ratios, low speeds and high torques. The proportion of
sliding is very high with this type of gearing. Our manufacturing accuracy for
the worm gear sets is in the range of DIN 3695-4. Due to different modules (profiles)
on the two flank sides of the tooth profiles, the tooth thickness changes over
the worm gear shaft. An axial displacement of the shaft in the worm wheel
allows the backlash to be adjusted almost to the point of "no
backlash". The gearing can be adjusted at maintenance intervals to ensure
Duplex gearing is
especially used in applications needing the highest precision. Many of our
customers come from precision mechanics so install the worm wheel sets in
positioning units or machine tools. In-house, the DUPLEX gears are used for
rotary indexing tables, dividing heads and combination applications.
In addition to the standard program
in the catalogue, a large number of customer-specific designs are manufactured
up to a center distance of 710 mm. A large warehouse and maximum flexibility in
production also allow just-in-time delivery. Depending on the customer
requirements, a wheel set calculation is carried out. Translations can be
calculated and manufactured at the factory. It is not always possible to use
existing gear cutting tools.
3° helix angle with grease lubrication
max. 2.5° helix angle when lubricated
with synthetic oils
from 3° to 5° helix angle with grease lubrication
from 2.5° to 4.5° helix angle when
lubricated with synthetic oils
There is no self-locking at pitch
angles of more than 4.5° or 5°. In addition, some factors can negatively affect
self-locking. If there are shocks or vibrations, there is the possibility that
the self-locking function will be lost.
Factors influencing self-locking
Factors influencing efficiency
Our gearwheel sets and gearboxes are used worldwide in a wide variety of industries and drive trains.
Examples are: Energy technology,
elevator technology, actuators, positioning tables, machine tools, lifting
systems and stage technology and also in other areas of application for general
Our many years of experience in the development and calculation of the drives are supported by well-known raw material suppliers. With the raw material, we carefully select the alloy composition for the respective application. Material certificates and material test certificates are readily available on request.
The worm shaft is made of
case-hardened steel. The flanks and bores are ground. The worm wheel is made of
bronze. Here, too, the customer can work with us to find the best selection for
the desired application.
Cu Sn 12 DIN 1705
Soft material with good wear
resistance for high sliding speeds.
Cu Sn 12 Ni DIN 1705
Other materials on request.
material with a high wear resistance due to the addition of nickel, suitable
for high sliding speeds
Plastic wheels can also be used. It should be noted that due to the poor thermal conductivity, it should only be used for low sliding speeds <1.5 m/s and medium tooth flank loads. The worm must be hardened and the flanks must be ground.
Plastic worm gears may be operated
with approx. 50% torque load of the bronze gears (MF mineral grease
The technical design of the DUPLEX
worm gear sets is based on the fact that both the worm shaft and the worm wheel
have different modules (profiles) for the left and right flank. With this
technology, the worm profile becomes stronger from pitch to pitch, so that
there is a reduction in play through axial displacement of the worm. The axial
displacement of the worm shaft is carried out either by a special adjustment
adapter available from the catalogue or by appropriate adjustment devices supplied
by the customer.
For standard drives, we ask that you follow the assembly instructions. When installing and adjusting customer-specific wheel sets, care must be taken to ensure that the contact pattern of the gearing is adjusted correctly.
By checking the position of the
contact pattern when installing, you can see whether there is an error regarding
the axial position of the worm wheel. The contact pattern should tend towards
the outside side if possible. If the direction of rotation changes (reversing
operation), the contact pattern should tend towards the middle.