Frequently asked questions - slewing ring bearings

FAQ regarding iglidur PRT slewing ring bearings

Are there PRT slewing rings for use in ESD or ATEX environments? Are PRT slewing rings electrically conductive?

For use in ESD or ATEX areas, we recommend using iglidur PRT slewing rings with stainless-steel rings and sliding elements made of iglidur F2.

Are PRT slewing rings suitable for use in contact with food?

Yes. iglidur FDA-compliant PRT slewing rings with iglidur A180 sliding elements and stainless-steel rings are available.

What is the heaviest load to which I can subject iglidur PRT slewing rings?

This depends on the size of the slewing ring. The maximum permissible load on the currently largest iglidur PRTs, PRT-01-300, amounts to 150kN statically in an axial direction, which corresponds to a weight of 15t. During movement, the permissible load is 90kN. For the smallest model, PRT-02-20 - for applications with small loads and simultaneously high cost pressure - the maximum load is 13kN statically and 4kN during movement.

What is the maximum possible speed for PRT slewing rings?

The maximum speed depends on the size. For the largest possible iglidur PRT slewing ring, PRT-01-300, this amounts to 50rpm; for the smallest, PRT-01-20, it is 300rpm.

How big are the tolerances of the PRT slewing ring bearings?

The PRTs' range of tolerance is independent of size and amounts to 0.25 millimetres both radially and axially.

The axial run-out is also independent of size and indicates the maximum height difference for a cycle. It amounts to 0.1 millimetres. The radial run-out indicates the maximum deflection in radial direction during one circulation, and amounts to 0.2 millimetres, independent of the installation size.

What are the differences between a PRT-01, -02, -03 and -04?

We can offer you four different PRT slewing ring series. Each series has its own strengths.
 
The PRT-01 is the classic slewing ring bearing. Due to its robust construction, it is characterised by a high torsional strength, and is the most durable PRT. The variety of designs ranges from a stainless-steel version with iglidur® F2 sliding elements for ESD conformity to different gearings.
 
The PRT-02 was developed to save as much weight as possible. With an outer ring made of anodised aluminium and two iglidur® J4 collar clamps, it is the lightest PRT slewing ring bearing, and also very resilient and rigid.
 
The PRT-03 was specifically designed for the low-cost market. Through consistent downsizing, an additional design has been created that relies even more on plastic. This economises on costs, but not on performance.
 
The PRT-04 is the high performer in our product range. It is 60% lighter, 50% more compact and 20% more cost-effective than PRT-01. In addition, you will benefit from an extensive and ever-growing modular system. 

Is it possible to drive my PRT with an engine?

In our product range, you can find different slewing rings with drive for robot joints.

In addition, we offer four different gears of the outer ring for our PRT-01 and PRT-04 slewing ring bearings. For a toothed belt drive, you can choose between the conventional toothed belt profiles T10, AT10 or HTD8M. Furthermore, a classic spur gearing according to DIN 3967 is available.
 
For an even more compact design, the PRT-04 is also available with a toothed inner ring according to DIN3967.

Is 300mm the largest diameter available?

Yes, 300 millimetres is the largest available diameter. However, it is possible to purchase universal sliding elements for the series PRT-01, which are suitable for slewing rings with a diameter of 500 to 5,000 millimetres.

Can I combine the different PRT models with each other?

Yes, you can. Our PRT-04 modular system is continuously growing, and gives you the possibility to combine different functions. Please contact us in this case. Choose your preferred means of contact and ​let us advise you without obligation and in detail​.

Are there any requirements for the surface in the bolting area?

Yes, the flatness must be 0.05 millimetres and the surface should have a hardness of at least HBW 50.

Do you have any more questions? You are welcome to contact us without any obligation.