A Franke Direct Drive bearing is basically a torque motor, which is a complete system, consisting of a Franke 4-point contact bearing, drive and control. Complete powertrain components, Franke Direct Drive bearings are ideal for when small mounting space meets dynamic agility.

The stationary bearing forms part of the stator, the moving bearing functions as a rotor of the electric drive. The motor is integrated directly into the housing. There are no additional components needed to mechanically set the bearing into transition which increased the efficiency of the system. Through the use of housing parts made of aluminium, the weight of the motor can be more than compensated.

Integrating a complete drive system into a Franke bearing housing, means that components which are usually subject to heavy wear can be disposed of entirely. Components such as: such as gears, drives, motors, gearboxes, drives, pulleys, shafts, chains, belts and pinions.

Without further mechanical parts, the driving force in the bearing and power transmission guarantees position accuracy even at high speeds.

Further benefits include:

Lightweight
Customisable
Compact design
Integrated system
Highly dynamic
No maintenance
No lubrication

More environmentally friendly

Direct Drive Bearings are available in a range of sizes from 100mm BPD up to 2000mm BPD dependant on your bespoke requirements.

However, we also offer 4 standard size Direct Drive Bearings which are in the following diameters: 100mm BPD, 215mm BPD, 320mm BPD, and 385mm BPD.

A Franke Direct Drive bearing is much lighter than a conventional steel bearing without a drive. Through the use of housing parts made of aluminium the weight of the motor is easily compensated.

Yes, we also offer 4 standard size Direct Drive Bearings which are in the following diameters: 100mm BPD, 215mm BPD, 320mm BPD, and 385mm BPD.

For our standard size Direct Drives bearings lead-times are approx. 6 weeks from placement of order.  For bespoke bearings lead-times are dependent on each client’s unique requirements.

Power ratings can be made bespoke to what your application needs.

However, if you purchase one of our 4 standard size bearings the power ratings are:

100mm BPD (LTD100)   1.8 – 7 A
215mm BPD (LTD215)   3.1 – 12.8 A
320mm BPD (LTD320)   4.3 – 21.6 A
385mm BPD (LTD385)   4.3 – 21.7 A

All Direct Drive bearings are lubricant free.

Speeds can be made bespoke to what your application needs.

However, if you purchase one of our 4 standard size bearings the speeds are:

100mm BPD (LTD100)   2140 1/min
215mm BPD (LTD215)   640 1/min
320mm BPD (LTD320)   300 1/min
385mm BPD (LTD385)   193 1/min

Weights are dependent on the type of Direct Drive you require and can be made bespoke to what your application needs.

However, if you purchase one of our 4 standard size bearings the weights are:

100mm BPD (LTD100)   8kg
215mm BPD (LTD215)   21kg
320mm BPD (LTD320)   44kg
385mm BPD (LTD385)   57kg

This is all dependant on the type of shock/vibration e.g: point loading or all-round loading.

Each case is dependent on a variety of variables. For more information please discuss with your Franke representative on 01772 780200.

A Franke direct drive allows for high torque at a defined number of revolutions per minute. Torque limits are dependent on the type of Direct Drive you require and can be made bespoke to what your application needs.

However, if you purchase one of our 4 standard size bearings the torque limits are:

100mm BPD (LTD100)    4.5 – 16 Nm
215mm BPD (LTD215)    26.4 – 105 Nm
320mm BPD (LTD320)    77– 329 Nm
385mm BPD (LTD385)    118 – 522 Nm

Upon request motors can also be installed with water cooling, leading to the torque loading being doubled.

The Franke wire race principle also offers the advantage of the free choice of material for the housing. Available in Steel, Aluminium, Carbon, Brass or Plastic. If you require an alternate material

please discuss with your Franke representative on 01772 780200.

No, currently Franke Direct Drive bearings are not vacuum compatible.

This depends on the design of the bearing assembly and must be checked in each individual case.

Franke standard bearings are not designed for permanent use under water and thus achieve a protection class of max. IP41.

Each Direct Drive bearing can be made bespoke to your requirements. However, Franke’s standard Direct Drive bearings are sealed from dust and foreign objects as standard.

Integration of the entire system means that motors can be built smaller, which leads to significant energy and space savings of up to 30%.

As a guide Franke Direct Drives perform between -10°C to +80°C without impaired performance.

The motors are designed for a continuous temperature of up to 120°C. The bearing assembly work as standard up to 80 °C and may have to be designed in a special way to meet higher temperatures.

Yes, Franke Direct Drive bearings are programmable to a range of rotations spinning both clockwise and anti-clockwise.

This is all dependant on the speeds you require your Direct Drive to run. However, as an example our industry leading CTI scanner Direct Drive bearings can reach speeds of up to 300rpm with a noise level below 60 dB(A).

Franke Direct Drive bearings can achieve repeatability of up to 10 microns.

Yes, we work with many engineers and inventors who have a very unique list of criteria. Our team of designers and representatives are able to work with you to determine your requirements and the specification required for the application.

Please discuss with your Franke representative on 01772 780200.

Torque motors are integrated directly into Franke bearing assemblies. You receive a completely installed system, with a gearbox is no longer required. With this system, it is possible to generate a rotational movement but also to position it or to execute definable steps.

A torque motor consists of two components, the stator with coils and the rotor with a permanent magnet. The current-flowing coils produce a time-variable electric field, which interacts with the constant magnetic field of the rotor. The resulting force is used to generate the torque. The torque motor allows high torque at a defined number of revolutions per minute. The distance between the stator and the rotor (air gap) is decisive for the magnitude of the torque. The pre-loaded Franke bearing ensures a constant air gap. If required a measuring system can be used to determine the motor position also.

The cables are customised according to customer requirements.
> Cable with plug (available in variable cable lengths)
> Cable open version with wire end ferrules (available in variable cable lengths)
> Plug attached to the bearing (specific to customer request)

In order to protect the motors from thermal overload, they are permanently temperature-monitored. Temperature-dependent resistors are installed for this purpose.

The following sensors are available:
> PTC thermistor (standard)
> KTY
> Twilling switch (Klixon; bimetal switch)

The motors can optionally be operated with water cooling. This leads to a doubling of the nominal torque.

All measuring systems available on the market can be integrated into the Franke bearing assembly. Very robust inductive measuring systems are used as standard. They are available as incremental or absolute systems in different accuracy classes.

The following interfaces are available:
> Incremental system: TTL, 1Vpp
> Absolute system: EnDat 22; Fanuc, BiSS, SSI – 1Vpp
> Absolute systems are i.d.R. 50% more expensive than incremental

The (closed) measuring tape is attached directly to the rotor and the measuring head is screwed to the stator. It is also possible to attach a measuring system to the mating structure if required.

Since the measuring tape is a closed ring, only certain diameters are available, which must be taken into account during the design process. For larger numbers, any diameter is available.

All motors are tested before delivery in accordance with the EC directive 73 / 23EWG and the standards EN 50178 and EN 60204.

A manual is provided with each Direct Drive bearing which includes general notes, safety instructions, connection diagrams and installation instructions.

All controllers available on the market can be used.
Franke recommends servo drives. These are characterised by a high-power density, with intelligent functionality and a compact design. The controllers offer very good control characteristics as well as programming capability and support standard communication protocols. The servo drives have a complete digital motion controller and support a large number of commutation modes and position feedback. We would be pleased to propose the appropriate controller for the customer application and commission

During a power failure the motor reduces speed slowly until it stops. Unless a phase shortfall is initiated over the performance part, then the motor brakes relatively quickly.

Alternatively, an additional braking system may be used.

No, because it must be fulfilled for the entire system and not for individual components only.

On request Franke Direct Drive bearings can be designed with:

> Water cooling, which will double the nominal torque.
> Measurement system – absolute or incremental encoders

We are able to work within any quantity of order, from one off prototype for your application, all the way through to mass production.