Linkedin-in Youtube
Home › FAQ

FAQ - Frequently Asked Questions

Everything you need to know about ComInTec brand products. Can’t find the answer you’re looking for? Contact us.

Torque limiters

A torque limiter (or safety clutch) is a very important mechanical device designed to protect the components of a machine from sudden overloads or jamming.

In physical terms, torque (or turning moment) is the measure of the force that causes an object to rotate around an axis. It is measured in Newton-metre (Nm).

Where force is the thrust required to move an object in a straight line, torque is the ‘thrust’ required to make it rotate.
In the case of power generated by electric motors, when selecting a torque limiter, torque is calculated as follows:

Calcolo coppia per scelta limitatore

Where:

  • Cn: Rated torque;
  • P: Motor power (kW);
  • N: Rotation speed (revolutions per minute = RPM);
  • 9550: Is a conversion constant;
  • Sn: Service factor that takes into account the efficiency of the machine, system or application.

The main difference between a friction-type model and a mechanical disengagement model lies in how the device handles and responds to overload.

Friction models are equipped with friction rings and, in the event of an overload, slip continuously once the pre-set torque value is exceeded, while remaining engaged at all times.

Mechanical disengagement models may be equipped with internal rollers and balls that separate the driving and driven components physically in the event of an overload. Subsequent re-engagement may be either manual, in the case of the free-rotation version, or automatic, in the case of equidistant versions, where re-engagement occurs approximately every 15°, or the phase (synchronous) version, where re-engagement occurs with each complete revolution (360°).

Torque limiters are incorporated into systems that require the transmission of motion between parallel or coaxial shafts.

In the parallel shaft configuration, a transmission component (pulley, sprocket, etc.) is fitted to the limiter to transmit motion to the second shaft. ComInTec offers complete assemblies, including the torque limiter and the transmission component.

In the case of the coaxial shaft configuration, a combination of a torque limiter and a coupling is used. This solution permits motion to be transmitted between the two in-line shafts, while simultaneously compensating for any misalignments in the assembly.

Thanks to dedicated interface flanges, ComInTec is able to integrate its limiters with its corresponding range of elastic and torsionally rigid couplings. Typical applications for friction-type torque limiters include:

  • Conveyor belts and conveyors;
  • Wind energy sector;
  • Solar trackers;
  • Access systems;
  • Compressors for lorries/HGV;
  • Earthmoving machinery.

Typical applications for slip-clutch torque limiters include:

  • Automatic machines;
  • Machine tools;
  • Shredders;
  • Water treatment systems;
  • Escavators;
  • Packaging and bottling machinery;
  • Labelling and blister-packaging machines;
  • Test benches.

ComInTec torque limiters are available in steel or stainless steel (designation -SS).
They can be supplied with either finished keyway bores (type A1) or blank bores (pre-drilled or solid hub).

The DSS/SG version is supplied exclusively with a finished keyway bore (type A1), to which the option of a finished bore with a shrink disc (type E) can be added.

The finished bore is machined to a roughness of Ra=1.6 with a standard tolerance of H7, while the keyway conforms to DIN 6885-1, with a standard tolerance of H9. ComInTec can produce bores and keyways with varying tolerances, according to the customer’s requirements.

Yes, ComInTec’s in-house technical department assists customers in customising torque limiters, optimising them to meet the specific requirements of each application, in terms of both performance and dimensions.

A torque limiter is calibrated by means of an adjustable ring nut: by screwing or unscrewing this nut varies the degree of compression applied to the disc or coil springs, thereby determining the desired tripping torque during rotation.

Thanks to its certified test benches and precision measuring instruments, ComInTec is equipped to calibrate the devices in-house. Alternatively, the Company provides detailed calibration tables in its user manuals, enabling customers to adjust their torque limiters in complete autonomy.

In recent years, ComInTec’s product portfolio has been expanded to include a range of stainless steel products for use in the food and pharmaceutical sectors, or simply for outdoor applications. The torque limiter models in this range are:

  • DF: Friction-type limiter;
  • DSS/SG: Backlash-free ball torque limiter.

As an alternative to using stainless steel materials, a chemical nickel plating surface treatment can be provided, offering anti-corrosion properties comparable to those of stainless steel, but with superior mechanical performance.

ComInTec has achieved ATEX compliance for use in potentially explosive atmospheres, with the following specifications, for two torque limiters:

  • DSS/SG/RF: backlash-free, free-rotation limiter with manual reset: II 2G Ex h IIB T5 Gb;
  • DSS/SG/RF/PR-V: backlash-free, free-rotation limiter with manual reset for gearboxes: II 2G Ex h IIB, T5 Gb, II 2D Ex h IIIB T100°C Db.

Compared to an electronic control system, a mechanical torque limiter offers:

  • Rapid and precise response: it reacts immediately in the event of an overload;
  • Versatility: Easily customisable for various applications;
  • Robustness: durable even under demanding conditions, without the fragility of electrical components;
  • Simplified maintenance: Requires less complex management, with no special configurations;
  • Direct control: It operates mechanically, without the need to process electrical signals;
  • Independent of power supplies: Not affected by electrical malfunctions or ‘disturbances’.
Pneumatic clutches

A pneumatic coupling is a mechanical component designed to connect and disconnect a section of the transmission line instantly.

The couplings designed by ComInTec serve a dual purpose: they can engage the drive system while also protecting the mechanical components connected to them.

The purpose of a pneumatic clutch is to engage a drive system, typically by connecting the driving part to the driven part, whereas the purpose of a torque limiter is to protect the mechanical components connected to it, by interrupting the transfer of power between the two shafts in the event of impacts, obstacles or other overloads during operation.

The couplings designed by ComInTec serve a dual purpose: they can engage the drive train while also protecting the mechanical components connected to them.

The main difference between a friction clutch model and a mechanical disengagement model lies in the way the device manages the transfer of power/torque.

Friction models are equipped with friction rings which, under pressure from the piston, generate torque to be transferred to the driven part. In the event of disengagement due to overload, these rings slip continuously when the pre-set torque value is exceeded, but remain connected at all times.

Mechanical models are equipped with internal rollers, which, under pressure from the piston, engage the driving part with the driven part. In the event of disengagement due to overload, the next re-engagement will occur automatically after 360°.

As these are pneumatic clutches with a torque-limiting function, ComInTec recommends stopping the drive immediately in the event of disengagement due to overload, in order to extend the service life of the device. The drive should be restarted at low speed or with the machine almost ‘at a standstill’.

Yes, ComInTec’s in-house technical department can help customers to personalise their pneumatic couplings, optimising them to meet the specific requirements of each application, both in terms of performance and dimensions.

All ComInTec couplings are manufactured entirely in-house from steel and can only be supplied with the respective drilling in the central supports of the finished bore with a keyway.

The finished bore is machined to a roughness of Ra=1.6 with a standard tolerance of H7, while the keyway complies with DIN 6885-1, with a standard tolerance of H9. ComInTec is able to produce bores and keyways with varying tolerances, according to the customer’s requirements.

Yes, in the case of a coaxial drive, it is possible to combine ComInTec pneumatic couplings with a connecting coupling, using suitable interface flanges to obtain:

  • A connection between the two shafts;
  • Compensation for misalignments;
  • Protection of mechanical components.

Currently, the ComInTec range does not include stainless steel couplings. However, our products may be customised with an electroless nickel plating treatment, which guarantees corrosion resistance comparable to that of stainless steel, but with superior mechanical performance.

At present, the ComInTec product range does not include couplings designed in accordance with the ATEX directive for potentially explosive atmospheres.

Pneumatic devices are calibrated by introducing pressurised air into the cylinder–piston assembly. The torque that can be transmitted at the output of the device is proportional to the input pressure. ComInTec provides tables and operation and maintenance manuals to assist end users when calibrating their couplings.

Typical applications for pneumatic couplings include:

  • Test benches;
  • Labelling machines;
  • Capping machines;
  • Blister-packaging machines;
  • Moulding machines;
  • Multi-line conveyor systems.
Coupling joints

A coupling joint is a key mechanical component used to connect two rotating shafts (or axles) so as to transmit motion, and, hence, power (torque), from one component to another.

Another important function of coupling joints is to compensate for unavoidable positioning errors between the two shafts to be connected, both during assembly and during operation:

  • Axial misalignments: Forward/backward displacements along the axis;
  • Radial misalignments: When the shafts are parallel but not aligned on the same axis;
  • Angular misalignments: When the shafts intersect at a certain angle.

Using an elastic coupling also helps to absorb and damp vibrations and any load peaks.

While a coupling serves only to connect two shafts together and compensate for misalignments between them, a torque limiter also protects the mechanical components connected to it by interrupting the transmission of power between the two shafts in the event of impacts, obstacles or other overloads during operation.

Yes, in the case of a coaxial drive, it is possible to combine a coupling with a torque limiter by using suitable interface flanges to obtain:

  • A connection between the two shafts;
  • Compensation for misalignments;
  • Protection of mechanical components.

Torsionally rigid couplings are used to connect two shafts together, guaranteeing excellent torsional accuracy by compensating for minor misalignments. These types of coupling are mainly used in:

  • Automation and robotics;
  • CNC machines;
  • The textile industry;
  • Systems that reverse direction frequently;
  • Systems with frequent start-stop cycles.

ComInTec also manufactures a fully rigid coupling (GRI), which acts as a single, solid component, preventing any misalignment between the two shafts; in practice, it acts as a connecting sleeve.

Elastic couplings, on the other hand, are designed to form a connection between two shafts with significant misalignments, as the flexible element is often made of an elastic material. Such couplings also offer the advantage of absorbing shocks, torsional vibrations and load peaks during operation. These types of coupling are mainly used:

  • For connecting electric motors;
  • For connecting pumps and/or compressors;
  • On conveyor belts;
  • In the agricultural sector.

ComInTec couplings are manufactured in steel (-ST code), aluminium (-AL code) and stainless steel (-SS code).
They can be supplied either without internal bores or with the relative finished bores, and various locking systems:

  • Keyway with orthogonal grub screw (type A1 locking system);
  • 1 piece clamp locking systems with keyway (type B1) or without keyway (type B);
  • Two-part split-clamp locking systems, with keyway (type C1) or without (type C);
  • Locking systems with internal or external shrink disc, on request.

The two-part, split clamp locking system can be used to fit couplings without the need to move the components to be connected.

The finished bore is machined to a roughness of Ra=1.6, with a standard tolerance of H7, while the keyway complies with DIN 6885-1, with a standard tolerance of H9. ComInTec is able to produce bores and keyways with varying tolerances, according to the customer’s requirements.

Yes, ComInTec’s in-house technical department assists customers in customising their coupling joints, optimising them to meet the specific requirements of each application, in terms of both performance and dimensions.

The key technical data required to identify and select the type and size of coupling are:

  • Rated working torque, which, in the case of power generated by electric motors, is calculated using the formula:

    Calcolo coppia per scelta limitatore
    Where:
    – Cn: Rated torque;
    – P: Motor power (kW);
    – N: Rotation speed (revolutions per minute = RPM);
    – 9,550: Conversion constant;
    – Sn: Service factor (machine/system efficiency).

  • Rotation speed;
  • The diameter of the two shafts to be connected.

Other secondary, but no less important, data include:

  • Type of motion (continuous, intermittent or reciprocating);
  • Maximum torque;
  • Start-up frequency;
  • Operating temperature;
  • Known misalignments to be corrected;
  • Operating environment.

In recent years, ComInTec has expanded its portfolio to include a range of stainless steel products, which are suitable for use in the food and pharmaceutical sectors, or simply for outdoor applications. The coupling models in this range are:

  • GAS: elastic coupling with a ‘star’ insert;
  • GTR: torsionally rigid disc coupling;
  • GRI: fully rigid coupling.

As an alternative to stainless steel, our products are also available with an electroless nickel plating surface treatment, offering anti-corrosion properties comparable to those of stainless steel but with superior mechanical performance.

ComInTec has achieved ATEX compliance for the following products, which are certified suitable for use in potentially explosive atmospheres (see specifications below):

  • GAS: flexible coupling with ‘star’ insert: II 2G Ex h IIB T6 Gb, II 2D Ex h IIIC T85°C Db X…;
  • GAS/SG/DBSE: flexible coupling with central spacer and double ‘star’ insert: II 2D Ex h IIIC T85°C Db X.

Drawing on many years of experience in the production of coupling joints, ComInTec has designed a range of couplings featuring a central spacer for connecting two shafts spaced up to a maximum of 4,000 mm apart. The available models are as follows:

  • GAS/SG/DBSE: Aluminium elastic coupling with central spacer and double ‘star’ insert;
  • GTR/DBSE: torsionally rigid coupling with central spacer and double stainless steel disc pack;
  • GSF/DBSE: Aluminium coupling with central spacer and double stainless-steel bellows.

These solutions are typically used for the following connections:

  • Lifting systems with actuators or jacks;
  • Handling units;
  • Photovoltaic systems;
  • Connecting bevel gearboxes located at a distance from each other.

We prioritize support, not selling.

At ComInTec our sales team thinks like engineers, delivering accurate answers and faster support to our customers. Contact us for free transmission parts information.