Speed gearbox

1.1 Company introduction 1.2 Application selection of Ever-power high swiftness gearboxes Ever-power has been energetic in mechanical engineering for 25 years. For nearly 25 years, we have been manufacturing gears and mechanical gearboxes. Our aim is to keep delivering state-of-the-art products to our customers through intensive primary engineering and product advancement. We apply a maximally innovative approach while addressing specialized problems and specific needs of our customers. Our goal is constant development of items with a higher degree of practical and quality parameters. We propose optimal solutions based on an intensive comprehension of each concrete application. We supply high-speed equipment units especially for thermal power station, heat plants, coal and oil sector or sugar refineries. High swiftness gearboxes are a key component for applications such: • Turbogenerator drives • Steam and gas turbine drives • Turbocompressor drives • Pump drives • Test benches Ever-power has custom in high rate applications since 1977. The worldwide installation foot of the parallel shaft gearboxes totals over 800 devices. The calculation and style software KISSsoft and a 3D CAD program SOLID-EDGE and also other instruments allow us to become maximally fast and versatile. Our team of style engineers cooperates with universities, study institutes and leading experts from all around the world. Ever-power uses state-of-the-art finite element method (FEM) software equipment for identifying and optimizing gear models properties.
2.1 Product introduction High-velocity gearboxes designed and produced in Ever-power are designated mainly for power generation industry, compressor and pump applications. The manufacture is carried out on the modern machine equipment and gearboxes are assembled using own components or components supplied by European manufacturers. All products undergo thorough testing on a powerful test bench. The design and gear strength calculation are performed in accordance to API 613 5th Edition and AGMA 6011*. Product types: RS and RU gearbox type is made to endure forces from meshing of dual helical gears. They are not made to withstand any exterior axial or radial load. R1T and R2T gearbox type is made to withstand forces from meshing of single helical gears and exterior axial and radial load. The transmission of external axial load from HS shaft to LS shaft can be by way of thrust collars. The gearbox is usually self supporting and doesn’t need any reinforcement. It includes a foot flange for mounting to a base and jack bolts (levelling bolts) for easy set up. The gearbox does not require any special maintenance. It is suggested to change the oil on regular basis or when changing the weather conditions – start to see the Operating Manual for details. Standard gearbox is modified for high speed operation in the temperature range between -50 / +50°C provided the oil preheating at low temperatures and oil cooling at high temperature ranges. Should the gearbox be managed in hazardous area or under other particular conditions, it has to be contractually agreed. The typical gearbox efficiency is generally higher than 98,5%. Total efficiency depends on plenty of factors, such as mesh losses, bearing losses, windage losses etc. Ever-power is competent to prepare personalized solution to increase the gearbox effi ciency up to 99,5%. mesh losses gearing is usually sized based on the transmitted power. Power is definitely distributed by a customer. It isn’t possible to reduce mesh losses considerably, however Ever-power aims to optimize the losses to achieve the best compromise as well as gear life, strength and NVH behaviour. bearing losses these losses possess the biggest influence on the gearbox efficiency. It is necessary to design and size the bearing properly. windage losses windage losses have big impact on the gearbox performance if the gear circumferential velocity is definitely high. You’ll be able to decrease these losses (up to approx 50%) by using the windage cover. other losses gearbox efficiency is also affected by the essential oil pump losses (if used), oil injection reduction etc.
2.3 Key specialized features Turbo Gear Units Catalogue © Ever-power Industry a.s. 2016, EN1604 Main Gearbox Components 2.3.1 Housing The housing includes 2 parts: the upper and the lower case. It really is fabricated steel building. The housing is optimized by CAE methods to ensure for good stiffness, low noise emissions, excellent cooling properties and minimum weight. In the low part there are foot for fixing the gearbox to the building blocks outfitted by jack bolts and with provision for mounting of earthing screw (if the gearbox is set to the hazardous area). Addititionally there is located the oil input/output fl ange and provision for temperature detectors conduction to the junction box. In the upper part there can be an inspection cover, looking at the proper lubrication of meshing gears, a breather and provision for vibration probes. Split encounter of the casing is definitely horizontal, parallel to shaft axis. Both parts are linked by bolts and fi xed by dowel pins. 2.3.2 Shafts and gears Both shafts are forged parts. HS shaft can be forged in one piece along with gearing. LS shaft and the gear are forged separately and the gear is temperature assembled on the shaft. The backsplash band is usually forged in one piece with the shaft or warmth assembled. Both gears are surface to high precision. Tooth fl anks of HS pinion have got special modifi cations to reduce the sound level and compensate the defl ection of shafts because of heavy load. A hunting tooth mixture exists for mating gears when a tooth on the pinion does not repeat contact with a tooth on the gear wheel until it has contacted all the other gear wheel teeth. The form of shafts ends depends on customer’s demand (cylindrical, tapered, fl anged etc.). Both shafts are dynamical balanced according to ISO 1940 or API 613. 2.3.3 Bearings Solely hydrodynamic bearings with more sliding faces are used due to high speeds and bearing load. These bearings are divided into bearings with: • fi xed geometry – there is absolutely no movement of sliding faces • tilting pads – sliding faces are planetary gearbox moving
LS (low quickness) shaft is generally placed in basic journal bearings with cylindrical clearance (fi xed geometry). One of the bearings can be radial (on the non-traveling end) and the other one (on the traveling end of the shaft) is mixed radialaxial bearing. The design and calculation of the bearings are performed according to the latest methods. Bearings on HS (high speed) shaft are often tilting pad type due to high quickness and pitchline velocity and both of them are radial bearings. Tilting pad bearings usually have 4 or 5 5 pads and static load direction goes either on one pad or between pads. Lubrication of these bearings could be reached by overflowing the space between pads or oil injection between pads by means of a number of nozzles which also shields pads against circumferential movement. When oil injection is used you’ll be able to reduce friction losses significantly. These bearings have the highest level of resistance against rotor instability because they don’t generate any load leading to instability
2.5 Gearbox Testing 2 Product description and key features 3 Gearbox selection 1 Introduction 2 Product explanation and key features 2 Product description and key features 2.5.1 Load lab tests of high-velocity gearboxes Testing laboratory for high-speed gearboxes is a camera monitored contemporary place of work at Ever-power manufacturing facility in Pilsen. The Powerful Check Bench is a assessment facility equipped with a computer controlled 1 MW engine with speed up to 3.600 rpm, controlled load by a generator up to 710 kW of power, auxiliary gearboxes enabling testing of the primary gearbox with increase to 35.000 rpm. The check bench possess a lubrication centre with adjustable oil fl ow from 10 to 1 1.600 liters/ minute, controllable oil temperature and water cooling up to 800 kW of power. The lubrication is certainly supported with pneumatic pumps providing full volume of oil in the event of power outage. The assessment process is immediately recorded while oil and bearing temperature, pressure, noise, complete and relative vibrations are measured and used in a control space for assessment by a specific software.