Worm and worm wheel gears

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 optimum transmission.

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.


    • Ideal for high precision requirements
    • Quiet running
    • Low vibration
    • Backlash: < 1 Arcmin. (0.016°)
    • 10 sizes: 35 to 200
    • Input speed up to 6,000 rpm.
    • Up to 710 mm center distance

Self locking

Dynamic self-locking

max. 3° helix angle with grease lubrication

max. 2.5° helix angle when lubricated with synthetic oils

Static self-locking

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

  • Pitch Angle
  • Surface roughness of the flanks
  • Sliding speed
  • Lubricant
  • Heating up

Factors influencing efficiency

  • Helix angle of the worm gear
  • Surface finish
  • Sliding speed
  • Lubricant
  • Installation conditions

Applications / Industries

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 drive technology.


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.

Soft 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 specifications).

DUPLEX system - backlash-free design

The DUBLEX system is a special version with reduced, adjustable backlash. 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.

Duplex wormgear setzoom

Assembly and installation

When installing and adjusting 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.



Flohr Industrietechnik GmbH - Im Unteren Tal 1 - D-79761 Waldshut-Tiengen - Phone: +49 (0)7751 / 8731-0 - info@flohr-industrietechnik.de

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