Regreasing Basis Brochure

58 Garnock Avenue Toronto, ON, Canada M4K 1M2 Phone: 416 466-3144 toll free 888 442-5008 Fax: 416 466-3807 www.fluidcenter.com ‘Providing Tribological Solutions’ ‘VSG’ VANE SPINDLE GREASE WICKET GATE LUBRICATION INTRODUCTION To ensure that units are available when required, operating efficiently and not incurring unnecessary maintenance costs, it is important that the wicket gate bearings and the regulating mechanisms receive sufficient lubrication. Too much can be wasteful and too little can lead to failures or at the least, wear, corrosion and/or higher forces to move the gates. The latter can result in overloading of other components. The grease also seals out dirt and water as well as prevent helps prevent corrosion of the bearings and journals. The first step is to refer to the turbine manufacture's original instructions and/or any subsequent notices on the lubricants and lubrication. Station experience, company procedures or input from company technical units can also be very useful in cases where the manufacturer's advice is not available or is very dated. The following material based on old information from Hydro-Québec can be used as a guide. It is expected that with modern formulations such as VSG grease that much less is required. This can be confirmed by monitoring wicket gates forces. Strain gauges and digital pressure gauges have been used. A greasing frequency of every week or two appears is common. FREQUENCY The pump for the lubrication system is to be operated as follows; a) Every 6 hours for turbines with a water head of <50 m (160 ft). b) Every 4 hours for heads between 50 m (160 ft) & 145 m (480 ft). c) Every 3 hours for heads >145 m (480 ft). QUANTITY The total grease volume in one bearing can be estimated as follows; Q (mm3) = 0.025 x Bearing dia. (mm) x Bearing length (mm) x 3.14, or Q (in3) = 0.001 x Bearing dia. (in) x Bearing length (in) x 3.14 This is not replenished every cycle because it should reportedly take three cycles to replace all the grease. Each greasing cycle will replace one third of the total amount. EXAMPLE For a turbine having a greasing interval of every six hours, 15 wicket gates with upper and lower bearings, 25 cm (10 in) in diameter and 46 cm (18 in) in length, this would be about 2 kegs of grease. This is just the wicket gate bearings so slightly more is required for all surfaces. Calculation - Grease volume: 15 gates x 2 bearings x 0.001 x 10 x 18 x 3.14 ÷ 3 regrease amount = 5.7 in3 X 4 intervals per day x 365 = 8,322 in3 ÷ 231 = 36 US gallons. Note that less is likely required with VSG. No warranties, express or implied, including warranties of merchantability or fitness for a particular use, are made with respect to the products described herein. Nothing contained herein shall constitute a permission or recommendation to practice any invention covered by a patent without a license from the owner of the patent. regreasebasis 9/06