Kaydon pitch and yaw upgrades

Reduce life cycle costs with Common causes of Ellipse truncation failure SKF and Kaydon failure In a pitch bearing, the contact area With the potential cost of downtime The classic failure modes predicted by between the ball and the raceway and bearing change-outs running standard bearing calculation models forms an elliptical shape that is into the hundreds of thousands of (i.e. fatigue spalling and brinelling) centered over the race contact angle. dollars, it pays to work with a supplier are actually very uncommon causes When the races are very thin or who can offer the upgraded bearing for failure. More often, pitch bearings inadequately supported, deformation solution that will improve productivity fail for reasons related to can cause the ellipse to drop off the and extend bearing life. degradation and/or lack of structural physical raceway surface, resulting in flexibility, including: truncation. Under severe truncation, Kaydon has over 30 years experience stress can cause the ball path edges designing and manufacturing slewing • Lubrication-induced failures from to break or the balls to fracture. bearings for turbine pitch and vibratory (), yaw positions. Serving the wind corrosion, denting, and surface- aftermarket for the past decade, induced fatigue Kaydon pitch and • Load and operation-induced solutions have been proven to failures such as component fracture reduce the total life cycle cost of (rolling elements, separators, races), wind turbines. separator lockup, and core crushing We’ve analyzed dozens of failed pitch bearings using laboratory- grade inspection systems and have documented the most common failures.

Pitch and yaw bearings Kaydon upgraded pitch bearing solutions

Every turbine system has unique Separator design • Wear-resistant ECOPUR® challenges. With over 30 years thermoplastic polyurethane lasts • Splitting the separator ring into experience in the industry, SKF and longer than conventional rubber segments with limited individual Kaydon are able to address these freedom of movement reduces • Responsive floating design provides challenges to decrease life cycle tensile/compressive load seal pressure when deformed costs and improve productivity. • Use of high-strength steel alloys Raceway hardening Kaydon can offer upgraded pitch improves durability, reducing bearing solutions that: contact wear and abrasion • Case depth tailored to application requirements prevents core crushing • mitigate edge loading and Raceway geometry failure strengthen the races • GD&T controls on path form and • Uniform hardness pattern along • address separator load and wear spacing improve load sharing and path surface absorbs heavy loads • prevent contamination ingress balance Packaging • retain lubricant • Smooth path finishes reduce skidding and internal friction • Coating of mounting holes helps • result in a better bearing prevent corrosion SKF patented high-endurance Kaydon pitch bearings address • Wrapping in VCI paper and seal design the following critical design packaging in vacuumed-sealed bags features: • ‘H’ seal cross-section profile and • Individual crating stacked in two- labyrinth retention groove prevent high sets Edge loading contaminant ingress • Increased path surface area Pitch bearing upgrades minimizes or eliminates contact truncation High-endurance seal • Added material strengthens rings and reduces deformation

Segmented Optimized separators case depth

Increased ball path surface

©2019 SKF USA Inc. and Kaydon Corporation skf.com | KaydonBearings.com The contents of this publication are the copyright of the publisher and may not be reproduced (even extracts) unless prior written ®SKF is a registered trademark of SKF USA Inc. permission is granted. Every care has been taken to ensure the accuracy of the information contained in this publication but no liability can be accepted for any loss or damage whether direct, indirect, or consequential arising out of the use of the information contained ®Kaydon is a registered trademark of the herein. Kaydon Corporation. Publication 700-615 (250/ANRO) Version 10/2019 Printed in the USA