An worm gear is characterized by its ability to achieve high torque transmission in a compact design. It finds Application in elevators, conveyor systems or in automation technology where low-noise operation and self-locking are required. Modern worm gears are efficient, durable and optimized for precise control tasks. In this article you will discover some of these gearboxes from various manufacturers.

Contents

• Worm gearboxes 2024 – The most important things in brief
• Worm gears – the new products
  • Two-stage worm spur gearbox with high ratios
  • Investigation of the load capacity limits on the worm wheel
  • Maintenance-free universal worm and bevel gears
  • Servo worm gear with high speed reserve
  • Small angle and worm gears now in the webshop
  • Precise combination of worm gear and encoder
  • Powerful worm gear with backlash from 3,3 arcmin
  • Worm gearbox with high efficiency
• Frequently asked questions

Worm gearboxes 2024 – The most important things in brief

Worm gears have proven to be crucial components in applications where compact solutions for high torquetransfers are required. Modern developments focus on increasing efficiency, longevity and reducing noise levels.

Especially in elevators, conveyor systems and in the Automation services offer worm gears through their self-locking property and the low-noise operation have significant advantages. Trends such as the integration of advanced materials and more precise manufacturing techniques allow for more precise control and improved load distribution, extending gear life.

Manufacturers rely on innovative technologies to... Performance and efficiency to improve their products. Here come specially developed ones Housingmaterials come into play. They enable improved heat dissipation, which extends the life of the gearboxes. Improving tooth flank treatment to minimize friction losses and reducing noise are on the manufacturers' agenda.

Modularity for flexible adjustments, compactness and precision as well as sustainable materials and energy-efficient designs complement the development trends, as do high-precision gearing technologies and improved lubrication systems to increase service life.

Worm gears – the new products

Below we present the new developments from various manufacturers on the market:

Two-stage worm spur gearbox with high ratios

February 15.02.2023, XNUMX | The worm-helical gearboxes of the ZK series from Groschopp has grown: The ZK30 combination of worm and spur gear stages allows high gear ratios and offers good efficiency. The gearboxes are made of aluminum in combination with induction or servomotors particularly efficient and economical. They are also robust, highly resilient and run quietly. Integrated mounting surfaces make the gearboxes versatile.

The ZK series is suitable for applications that require an angled outlet or a compact size. The nominal torque of the ZK30 worm gear is 30 Nm, further versions for 50 Nm are being planned. With ratios from 34,5:1 to 690:1, the combination gearbox achieves significantly better efficiency than two-stage worm gearboxes. Worm stage and helical gearing in the spur gear stage enable quiet operation of the easily mountable gearbox.

For applications in harsh environments such as food technology, pharmaceutical or chemical industries as well as in offshore use, there is an easy-to-clean one Version in stainless steel. Other features include: Ball bearing as well as the 14mm solid shaft or 15mm hollow shaft in the output. The load capacity of the worm shaft is 300 N radially and 140 N axially.

Investigation of the load capacity limits on the worm wheel

15.03.2021/XNUMX/XNUMX | the Drive Technology Research Association e. V. (FVA) makes a recommendation for examining the load capacity limits of worm gears. In a worm gear, the worm wheel is usually subject to comparatively high levels of wear. Sometimes this is desired, whenever it is used to run in or adjust the flank of the worm wheel to that of the worm, which increases the load capacity. However, after running in, wear and tear can mean a limit to the load-bearing capacity. Because increasing wear can lead to tooth failure.

In addition to the continuously progressive wear and tear, dimples in the shape of a Fatigue damage arise. Dimples are caused by cracks on or just below the surface. You get into the material into it and can then come back to the surface. Then pieces of material break off and leave gaps in the active flank surface. Those are the dimples.

Dimples increase wear

If the resulting dimples cause parts of the tooth flank break away, this in turn leads to increased wear because the flank is not completely available for load transfer and the remaining flank areas are therefore subject to higher loads. The interaction between wear and pitting distorts the results of pure wear tests due to the appearance of pitting. If no pits form, the wear intensity for the material-lubricant pairing can be determined in comparatively simple tests. This can be used to determine the service life of the gearing.

For efficient and reliable determination of the Wear intensity of worm gears, the operating conditions of experimental tests should be chosen so that no dimples occur. The operating conditions under which dimples occur would have to be determined in order to recommend action for resource-optimized and, if necessary, to develop a concise implementation of experiments.

The goal should be the Trial duration to be reduced to 10 to 15%. Example, i=50, n1=500 rpm against wear, 3.000.000 load changes (after the contact pattern has been developed) means 10 rpm 600 revolutions/h for the wheel and thus a test time of 5000 h to realize 3 million load changes. An acceptable test time would be e.g. B. 500 to 750 hours.

Maintenance-free universal worm and bevel gears

May 29.05.2018, XNUMX | The new worm gears from are particularly compact and powerful at the same time Norelem. The angular gears are maintenance-free thanks to a special, encapsulated aluminum housing: This reliably prevents grease from escaping or the effects of dust, which also has a positive effect on the service life. The directions of rotation are arbitrary for both types of gears.

The universally applicable worm gears are available in one size with a center distance of 20 mm and with 7 different ratios 13: 1 to 65: 1. The left-handed worm wheel is made of special brass, the worm itself is made of case-hardened steel. This combination of materials ensures smooth power transmission and high efficiency. The maximum axial and radial loads are between 200 and 500 N. There are
Output torques of up to 15 Nm can be achieved, with the drive speed up to 1000 min^-1 may be.

In the Bevel driven Customers can choose between seven different sizes with leg lengths from 32 to 60 mm. With a ratio of 1:1, they cover a wide range of applications with torques of up to 10 Nm. They are equipped with surface-hardened steel bevel gears and ball-bearing shafts. The bevel gearboxes can be mounted in all installation situations using a simple screw fastening.

Servo worm gear with high speed reserve

22.09.2016 | Wittenstein Alpha presents the expanded portfolio of servo worm gears from the “V-Drive” product family. The newly developed V-Drive Basic is initially available in two sizes with basic output type hollow shaft and solid shaft as well as a total of five gear ratios. The torsional backlash of 10 to ≤ 15 arcmin is specified for all versions.

The special geometry and design of the gearing in V Drive Basic ensures a high speed reserve and high efficiency. This also makes the servo worm gears very smooth and quiet with a maximum of 65 dbA at full load and only around 50 dbA at medium speeds.

The Upgrade versions V-Drive Value and V-Drive Advanced are fully compatible with the V-Drive eco and V-Drive⁺, but offer increased torques and significantly reduced backlash. In addition, both V-Drive versions are specified for a lifetime of over 20.000 operating hours - a value that is about 25 to 50% above the current market standard.

Small angle and worm gears now in the webshop

April 16.04.2014, XNUMX | In addition to the well-known cubic bevel gears and the miniature gears Madler now also offers the KEK bevel gear units. They are available in seven sizes with a gear ratio of 1:1 with shaft diameters of 6 to 12 mm. The new KES worm gear units offer a particularly small center distance of 20 mm in seven gear ratios.

In addition, these two offer Angle gear-Designs from German production ensure high torque transmission with small dimensions. They can be mounted in all construction positions and allow various mounting options in various housing designs. By using these maintenance-free grease-lubricated gearboxes, the dimensioning and production costs of systems and devices can be further optimized. The gearboxes are now also available online.

Precise combination of worm gear and encoder

October 31.10.2013, XNUMX | Expanded with two new worm gears and two new encoders Buehler its flexible solution matrix Engines, gearboxes, Enodern and Brakes. The version of the new worm gear transmission equipped with brass gears stands for maximum load capacity and reductions of up to 50:1. The version with Plastic gear covers the reduction ranges from 10: 1 to 15: 1 and is particularly recommended as a cost-effective variant.

These gearboxes, in which the output shaft is perpendicular to the motor, can be optimally combined with the brushed 52 mm and 63 mm DC motors as well as with the brushless 63mm EC motor. The two can also be combined Encoder with these drives. Available as high resolution optical encoder with 2 channels and 100 signals per revolution or as a particularly robust 2-channel 2 cpr magnetic encoder for use even under particularly harsh environmental conditions. With an additional cap, a protection class of IP 54 can be achieved. Such drives are used in Building automation, agricultural technology and transport.

Powerful worm gear with backlash from 3,3 arcmin

November 18.11.2011, XNUMX | New in the portfolio of System is the worm gear S030-50, which offers force deflection by 90 degrees with the highest precision. The mechatronics team managed to put together a particularly precise and powerful worm gear. The ratio of 50:1 converts the maximum drive torque of 0,24 Nm into an output torque of 12 Nm. The high-precision gear doesn't just shine with its maximum backlash of just 3,3 arcmin.

The 1kg gearbox in the Aluminum housing Measuring 92 x 44,5 x 92 mm, it has a worm made of steel and a worm wheel made of aluminum bronze with a 14 millimeter diameter hollow shaft. With its integrated Hall sensor, which defines the reference point, it is particularly suitable for precise angular positioning.

The reason for developing the drive component was to design it ready for installation positioning system "Driveset M108R". This is a linear system with an additional rotation module. This automation component is very suitable for Image Processings or test automation applications. The designers discovered that the market did not offer a suitable worm gear for the required rotation module. Class characteristics of 5 min were required^-1 and a thrust force of 30 N of linear motion at a repeat accuracy of 0,25 degrees of rotation.

Harmonic gears for industrial robots, cobots and handling

For the drive set, the gearbox works as the first axis moving the tool in a kinematic structure with a two-phase stepper motor. Also the Linear axis is done by one stepper motor driven. The motor drivers are integrated into the “Xemo” controller that is part of the system. 

Worm gearbox with high efficiency

13.05.2011 | Groschopp now has the powerful VE40 worm gearboxes in its range with a nominal torque of up to 45 Nm depending on the selected gear ratio. These have a similar modular structure to the VE31 and can be combined with flanges and gear feet and can be operated variably in all positions on the engine. Especially in the low gear ratios, the VE gearboxes achieve a remarkable degree of efficiency for worm gearboxes. The VE40DB version with ratios of up to i=15 has values ​​of 0,8 and above.

VE gearbox are characterized by their longevity and their particularly quiet operation. Compared to the previous model, the maximum permissible power loss has been increased, which is now 95 W, four times higher than the VE31. In addition to a large selection of gear ratios, there is a corresponding variety of housings. The VE series is available with a cover, foot or various flanges and is therefore also compatible with standard motors. Custom-made versions of these series are available as an option.

The output shaft of the Full shaft version can protrude freely on one or both sides as required by the application. At the hollow shaft version The input shaft is mounted and allows standard drives to be easily attached. The hollow shaft design can also be easily converted into a solid shaft design using a separate plug-in shaft, thus offering maximum flexibility. This stub shaft can be mounted on the right or left. As a solid shaft version, the gearbox has an even higher efficiency than the hollow shaft version.

Frequently asked questions

How does a worm gear work?

A worm gear works by having a helical snail, which rotates, engages the teeth of a worm wheel. This configuration allows torque to be transferred from the worm to the wheel. The main advantages of a worm gear are a high gear ratio in a compact design, the ability to move large loads with low noise, and often a self-locking mechanism that prevents the system from spinning back under load.

Where is a worm gear used?

Worm gears are used in Applications used that require high gear ratios in a compact format. Typical areas of application include conveyor systems, elevators, automated doors, telescopes, in automation technology for precise motion control and wherever low-noise and low-friction transmission of large loads is necessary. Their ability to self-lock makes them particularly useful for applications that require a safety feature to prevent movement when no motive force is applied.

When are worm gears self-locking?

Worm gears are self-locking, if the slope of the worm is so low that the friction between the worm and the worm wheel prevents the gear from turning back under load. This depends on the geometry of the screw, the coefficient of friction of the materials and the angle of the screw pitch. 

Source: This article is based on information from the following companies: Bühler, FVA, Groschopp, Mädler, Systec, Wittenstein.

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