Frequently asked questions - slewing ring bearings

ESD- & ATEX environments

Are PRT slewing rings available for use in ESD or ATEX environments? Are PRT slewing rings electrically conductive?
For use in ESD or ATEX areas, we recommend the use of iglidur PRT slewing rings with stainless steel rings and sliding elements made of iglidur F2.

FDA conformity

Are PRT slewing rings suitable for use with food contact?
Yes. iglidur FDA-compliant PRT slewing rings are optionally available with iglidur A180 sliding elements and stainless steel rings.

Loads

How high can I load iglidur PRT slewing rings?
This depends on the size of the slewing ring. The maximum load of the currently largest iglidur PRT, PRT-01-300, is 150kN in the axial direction, which corresponds to a weight of 15 tonnes. The dynamic load rating is 90kN. For the smallest model PRT-02-20 (applications with low loads and high cost pressure at the same time) the maximum load is 13kN static and 4kN dynamic.

Speed

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 it is 50rpm, for the smallest slewing ring PRT-01-20 it is 300rpm.

Tolerances

What are the tolerances of PRT slewing ring bearings?
The tolerance clearance of the PRT is independent of the size and is 0.25mm both radially and axially.

The axial run-out is also independent of the size and indicates the maximum height deflection in one revolution. It is 0.1mm.

The radial run-out indicates the maximum deflection in the radial direction in one revolution and is 0.2mm regardless of the size.

The sizes

What are the differences between a PRT-01, -02, -03 and -04?
We have four different PRT slewing ring series on offer. Each series has its own individual strengths.
 
The PRT-01 is the classic slewing ring bearing. Due to its robust design, it has a high torsional strength and is the PRT with the highest load capacity. The variety of versions ranges from a stainless steel version with iglidur® F2 sliding elements for ESD conformity to versions with different toothings.
 
The PRT-02 was developed with the aim of saving as much weight as possible. With an outer ring made of anodised aluminium and two inner rings made of iglidur® J4, it is the lightest PRT slewing ring bearing with high load capacity and rigidity at the same time.
 
The PRT-03 was specially designed for the low-cost market. Consistent downsizing has resulted in an additional type that focusses even more on plastic. So you save on costs, but not on performance.
 
The PRT-04 is the high performer in our range. 60% lighter and 50% more space-saving compared to the PRT-01, yet 20% more cost-effective. You also benefit from an extensive and constantly growing modular system.

Motor connection

Is it possible to drive my PRT with a motor?
Our range includes various slewing rings with drive for robot joints.

In addition, we offer four different toothing options for the outer ring of our PRT-01 and PRT-04 slewing ring bearings. For a drive with a toothed belt, you can choose between the standard toothed belt profiles T10, AT10 or HTD8M. The classic spur gear toothing according to DIN3967 is also available.
 
For an even more compact design, the PRT-04 is also available with a toothed inner ring in accordance with DIN3967.

Diameter size

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

Combination options

Can I combine the different PRT models with each other?
Yes, you can. Our PRT-04 modular system is constantly growing and offers you the option of combining different functions. Discover the modular principle here.

Screw connection

Are there any requirements for the surface in the area of the screw connection?
Yes, the flatness must be 0.05mm and the surface should have a hardness of at least HBW 50.