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Transmitting large forces around corners
Worm gear sets from Framo Morat
If your application requires high torque, high gear ratios in a single stage, and a 90° power transmission, Framo Morat offers two options:
- Our high-precision worm gear sets are a proven drive solution for countless applications. They are technically refined and have been tested thousands of times in practice.
- These innovative speeroX gear sets are ideal for transmitting high torques with a high degree of efficiency in compact spaces.
Framo Morat’s advanced manufacturing methods and many years of experience in development and production have made our worm gear sets a byword for quality. The combination of precisely manufactured worms and worm wheels ensures smooth, quiet power transmission and a long service life with low maintenance. A special feature of worm gear sets is their self-locking capability: This prevents the gearbox from turning in the opposite direction when the driving force is removed. This feature is particularly important in safety-critical applications.
We offer our worm gear sets through two distribution channels: as catalog products and as customized designs.
- Our catalog worm gear sets, which are made to the Framo Morat standard, are available in a variety of finely graduated options for center distance, gear ratio, and output torque, and are usually available from stock via our online shop.
- Customized worm gear sets are developed precisely according to your specifications. We design the gearing, define the materials and surface treatments, and advise on lubrication and torque loads.
What application do you need worm gear sets for?
Partnering with Framo Morat – Your Advantages
All quality-critical soft and hard machining steps, including hardening in our own heat treatment furnaces, are carried out on our in-house production lines. Thanks to these extensive in-house manufacturing capabilities, we can perform even complex machining tasks precisely according to your specifications and the highest quality standards. Our production capability is demonstrated by the fact that we produce more than 1.5 million worm gear sets in-house per year.
Catalog worm gear sets made to the Framo Morat standard
With the standard gear sets from our catalog, you receive precisely manufactured, high-performance, and long-lasting gearing solutions for a wide variety of applications. You can purchase the combinations of worm and worm wheel directly from our Online-Shop.
- Center distances from 17 to 80 mm
- Worm wheel diameters from 20 to 135 mm
- Gear ratios up to 100:1
- Worms made of case-hardened steel
- Worm wheels made of special brass alloy
Customized worm gear sets
For special requirements, you can have gear sets developed and manufactured to your specific needs, with individual materials, module sizes, and geometries – often the most technically and economically efficient solution.
- Center distances up to 210 mm
- Worm wheel diameters up to 300 mm
- Worm diameters up to 120 mm
- Worm shaft lengths up to 500 mm
- Individually designed gear geometries, application-specific materials and interfaces
Duplex worm gear sets
Duplex worm gear sets are ideal for drives that require high gear reduction and precise angular positioning. The tooth flanks of duplex worms in duplex gearing are not uniformly shaped, but rather, they feature different lead angles. They are typically steepest in the middle of the worm and become progressively shallower toward the edges. If the backlash increases after prolonged operation, the gearing can be adjusted to minimize play by slightly shifting the worm shaft axially.
Duplex gearing is typically used in high-precision applications, such as metrology, medical technology, and rotary and swivel tables that position workpieces for machining. The adjustable gearing ensures precise positioning throughout its entire service life.
Worm gear sets in detail
Worms
- Worms made of steel
The worms are generally made from case-hardened steel. The flanks and bores are ground.
Worm wheels
- Worm wheels made of brass
These worm wheels are made from a special copper-zinc alloy with aluminum, silicon, and manganese additives. This special grade was developed specifically for sliding applications.
Brass worm wheels offer good corrosion resistance, high strength, excellent sliding properties, and high wear resistance. Due to their aluminum content, they also have excellent chemical resistance.
The lead content in brass worm wheels is ≤ 0.1 percent by weight.
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Worm wheels made of plastic
Due to their lower thermal conductivity, plastic worm wheels are suitable primarily for low sliding speeds and medium tooth flank loads. For combination with a plastic worm wheel, the worm must be hardened and the flanks ground.
The coefficient of thermal expansion of plastic is approximately four times greater than that of brass. For this reason, the backlash (flank clearance) should not be too small.
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Worm wheels made of bronze
Different alloys can be used to optimize bronze worm wheels for various loads and speeds:
CuSn12, according to DIN EN 1982, is a relatively soft material with good wear resistance and is suitable for high sliding speeds.
CuSn12Ni, according to DIN EN 1982, is a relatively soft material with very high wear resistance and is suitable for very high sliding speeds.
CuAl10Fe5Ni5, according to DIN EN 1982, is a relatively hard sliding material suitable for high loads and relatively low speeds.
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Worm wheels made of cast iron
EN-GJS-400-15 DIN EN 1563 and EN-GJL-250 DIN EN 1561 are suitable for low sliding speeds.
A gearbox is self-locking if it can be driven via the input shaft, but not via the output shaft. In a worm gear set, self-locking can occur with certain combinations of lead angle, lubricant, gearbox temperature, sliding speed, and surface roughness of the mating tooth flanks. There are two types of self-locking: static and dynamic.
- In static self-locking, the worm gear cannot be driven out of the rest position by the worm wheel. Static self-locking is expected at lead angles from 3° to 5° with grease lubrication and from 2.5° to 4.5° with synthetic oil lubrication
- Dynamic self-locking occurs when the drive train stops after the drive motor is turned off. Dynamic self-locking is expected at lead angles of up to 3° with grease lubrication, and up to 2.5° with synthetic oil lubrication.
No self-locking is present at lead angles above 4.5° or 5° respectively.
Shocks and vibrations can cancel out self-locking. Certain combinations of lubrication, sliding speed, and load can create favorable sliding properties that may eliminate self-locking. For this reason, warranty claims regarding self-locking are excluded.
The reference surface tolerances determine the lateral positioning of the worm wheels. The lateral tolerance c must not exceed 0.15 mm for any center distance.
You can determine if the worm wheel is in the correct axial position by checking the tooth contact pattern position when the gear wheel is installed. Ideally, the tooth contact pattern should tend toward the run-out side. When the gear is turned in the opposite direction (reversing), the tooth contact pattern should tend toward the center.
The efficiency of a worm gear set generally depends on the following factors:
- Lead angle of the worm
- Sliding speed
- Lubricant behavior
- Surface quality
- Installation conditions
The larger the center distance, the greater the efficiency. For small center distances, sliding bearings are often used for space and cost reasons; their increased friction coefficient can significantly affect the overall efficiency. The efficiencies specified in the worm gear set catalog apply only under optimal installation conditions.
Helical gearing is a type of spur gear inclined at the same angle as the lead angle of the worm. While a worm and worm wheel make contact along a line, helical gearing has a point contact. As a result, only a reduced torque can be transmitted, or the service life is shortened. For a technically reliable solution, we generally recommend using a worm gear set.
Possible applications for worm gear sets
Worm gear sets solve a fundamental challenge faced by electric motors: they convert fast rotational movements with low torque into high torque at low speeds. That is why our gear sets are used successfully in numerous industries and applications: in mechanical engineering and measurement and control technology, as well as in renewable energies and demanding medical technology applications.
Worm gear sets for drive technology
Our standard worm gear sets are typically used in geared motors. Thanks to our extensive in-house manufacturing capabilities and comprehensive quality assurance, Framo Morat worm gear sets are regarded as the epitome of precision with reliable, long-lasting performance. It’s no coincidence that renowned gearbox, motor, and drive manufacturers use our worm gear sets in applications around the world.
Our worm gear sets also play a key role in our Compacta series geared motors and numerous custom-engineered drive systems.
Worm gear sets for medical technology
Worm gear sets used in medical applications must have drive components that meet the highest standards of precision, smooth operation, and durability. To enable the surgical team to provide the best possible care for patients, the table surface is divided into multiple segments that can move independently. We developed and manufactured stainless steel worm gear sets for this application that are exceptionally lightweight, quiet, and long-lasting. These gear sets ensure precise, jolt-free adjustment of the operating table.
Worm gear sets for pump systems and chemical plants
Our worm gear sets are frequently used in pump systems for water treatment and drinking water purification. They provide the necessary gear reduction, and their offset axes allow motors to be mounted in a space-saving manner, parallel to the pipelines. High-quality materials and precision manufacturing ensure the reliability and longevity of our gear sets during continuous operation.
Worm gear sets for communication technology
In satellite communication, precise antenna alignment is crucial for stable signal transmission. Framo Morat's high-precision, low-backlash worm gear sets ensure the rotary heads’ accurate angular positioning of azimuth and elevation. Our high-precision, weight-optimized duplex worm gear sets ensure top-level communication in Transport Layer constellation satellites, for example.
Worm gear sets for machine tools
In EDM machines, laser cutting systems, and many other CNC-based machining centers, rotary tables allow workpieces to be machined from all sides without reclamping. To meet the high demand for positioning accuracy, we developed and manufactured a worm gear set with duplex gearing. The adjustable gearing enables precise angular positioning of the rotary table throughout its service life.
Worm gear sets for renewable energy applications
Tracking systems for solar installations can significantly increase energy yield at a moderate additional cost. Worm gear sets are the drive mechanism of choice in these systems, because their self-locking feature eliminates the need for an active brake. Our custom-engineered gear sets can withstand dynamic loads of up to 9,000 Nm and static loads of up to 20,000 Nm. This allows a single drive unit to track the sun's position for up to 60 m2 of panel surface area.
Worm gear sets in industrial spindle-type lifting gears
Spindle-type lifting gears lift, adjust, and position heavy loads with millimeter precision. This is achieved by compact drive components that reliably transmit high forces. Framo Morat’s precision-manufactured worm gear sets drive the spindles, enabling controlled linear motion. With center distances of up to 80 mm and gear ratios of up to 80:1, these gear sets are ideal for powerful lifting applications in confined spaces. The self-locking gearing securely holds loads in position even without an active drive. Worms made from case-hardened steel and worm wheels made from wear-resistant composite metal ensure reliable performance in demanding industrial applications.
Worm gear sets in bionic hand prostheses
Bionic hand prostheses make everyday actions like typing, grasping, or writing possible again. Framo Morat’s worm gear sets convert myoelectric signals into precise movements – quietly and reliably, within a very compact space. The self-locking effect of the worm gearing allows the finger position to be held securely, even without active power. Thanks to the compact design, the overall weight of the prosthesis remains comparable to that of a natural hand, while the noise-optimized operation ensures discreet everyday use.
References (selection)
Worm Gear Sets for sMove Gates by SKIDATA
Access systems from SKIDATA used in mountain sport destinations and parking solutions must operate reliably year-round — even under wet conditions, temperature fluctuations, and high mechanical loads. To meet these requirements, Framo Morat’s worm gear sets were designed as compact drive units for integration into the sMove Gates: high gear ratios in a single stage, 90° power transmission, and space-saving integration into the gate design. The smooth power transmission ensures low-noise operation and consistently stable performance over time. For outdoor applications, the worm gear sets are manufactured from corrosion-resistant steel and are available in both left-hand and right-hand configurations.
Spindle lift gearboxes for industrial lifting applications
Framo Morat supplies precision-manufactured worm gear sets for the C-series spindle lift gearboxes from NEFF Gewindetriebe, which reliably transmit maximum forces while enabling smooth, controlled linear motion. The gear sets are designed for center distances up to 80 mm and transmission ratios up to 80:1 – ideal for powerful lifting units in confined spaces. Thanks to the self-locking gearing, the load remains securely in position even without active drive. Case-hardened steels and wear-resistant composite metals ensure a long service life, smooth running, and maximum reliability in continuous industrial use.
Belt drives for manufacturing and intralogistics
Belt drives in intralogistics and industrial production often run continuously, so they need to operate quietly, reliably, and efficiently. They must also be compact enough to easily integrate into conveyor systems. We designed precision worm gears with a very small center distance of 40 mm and a reduction range up to 50:1 for the GB-140-Getriebe der Württembergische Elektromotoren GmbH (WEG). With a torque of 25 Nm, they are ideal for smooth, quiet transport tasks during continuous operation.
Automatic size adjustment in packaging automation
Slim bottles, bulbous jars, voluminous PET containers: Automated size changeovers in filling plants require highly dynamic yet precise and reliable drive solutions – such as the worm gear drives from our customer, Ruhrgetriebe. Framo Morat supplies custom-engineered worm gear sets for these drives that execute rotational adjustment movements with precision, quiet operation, and repeatability – even in tight installation spaces. Thanks to their self-locking feature, they maintain their position even without power – a tailor-made solution for the dynamic demands of the food industry.
Power tillers for gardening and landscaping
Digging, clearing, and tilling are easily handled by STIHL power tillers. Framo Morat manufactures worm gear sets for various models. Since the worm wheel sits in the main drive train and drives the hoe shaft, design priorities focus on high load capacity and fatigue strength. Using a fully globoidal worm gear set optimally distributes the load between the worm and worm wheel, significantly increasing load-bearing capacity. The worm wheel's special copper alloy ensures reliable heat dissipation and the necessary fatigue strength.