1.1 Company introduction 1.2 Application selection of Ever-power high speed gearboxes Ever-power has been active in mechanical engineering for 25 years. For nearly 25 years, we’ve been production gears and mechanical gearboxes. Our goal is to keep providing state-of-the-art products to our customers through intensive core engineering and product development. We apply a maximally creative approach while addressing technical problems and specific needs of our customers. Our goal is constant development of products with a higher degree of useful and quality parameters. We propose optimal solutions on the basis of a thorough 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 velocity gearboxes are a crucial component for applications this kind of: • Turbogenerator drives • Steam and gas turbine drives • Turbocompressor drives • Pump drives • Test benches Ever-power has custom in high velocity applications since 1977. The worldwide installation base of the parallel shaft gearboxes totals over 800 units. The calculation and design software KISSsoft and a 3D CAD program SOLID-EDGE and also other instruments enable us to be maximally fast and versatile. Our team of design engineers cooperates with universities, research institutes and leading specialists from all around the world. Ever-power uses state-of-the-art finite component method (FEM) software tools for identifying and optimizing gear products properties.
2.1 Product introduction High-speed gearboxes designed and manufactured in Ever-power are designated primarily 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 producers. All products undergo comprehensive testing on a dynamic test bench. The look and gear power calculation are performed according to API 613 5th Edition and AGMA 6011*. Item types: RS and RU gearbox type is designed to endure forces from meshing of double helical gears. They are not designed to withstand any external axial or radial load. R1T and R2T gearbox type is designed to withstand forces from meshing of solitary helical gears and exterior axial and radial load. The transmission of external axial load from HS shaft to LS shaft can be through thrust collars. The gearbox can be self supporting and doesn’t need any reinforcement. It has a foot flange for mounting to a base and jack bolts (levelling bolts) for easy set up. The gearbox will not require any unique maintenance. It is recommended to change the essential oil on regular basis or when changing the environment conditions – start to see the Working Manual for details. Regular gearbox is adjusted for high speed procedure in the temperature range between -50 / +50°C provided the essential oil preheating at low temps and oil cooling at high temps. If the gearbox be operated in hazardous area or under other special conditions, it needs to be contractually agreed. The standard gearbox efficiency is usually higher than 98,5%. Total efficiency depends on plenty of elements, such as mesh losses, bearing losses, windage losses etc. Ever-power is competent to prepare customized solution to raise the gearbox effi ciency up to 99,5%. mesh losses gearing can be sized predicated on the transmitted power. Power is usually distributed by a customer. It isn’t possible to reduce mesh losses considerably, nevertheless Ever-power aims to improve the losses to attain the best compromise as well as gear life, planetary gearbox sturdiness and NVH behaviour. bearing losses these losses have the biggest impact on the gearbox performance. It is necessary to design and size the bearing properly. windage losses windage losses have big influence on the gearbox efficiency if the gear circumferential velocity can be high. You’ll be able to reduce these losses (up to approx 50%) by using the windage cover. various other losses gearbox efficiency can be affected by the oil pump losses (if utilized), oil injection loss etc.
2.3 Key technical features Turbo Gear Units Catalogue © Ever-power Industry a.s. 2016, EN1604 Main Gearbox Components 2.3.1 Housing The housing consists of 2 parts: the upper and the lower case. It is fabricated steel building. The housing is optimized by CAE methods to ensure for good stiffness, low noise emissions, excellent cooling properties and minimal weight. In the lower part there are ft for repairing the gearbox to the foundation equipped by jack bolts and with provision for installation of earthing screw (if the gearbox is set to the hazardous region). Addititionally there is located the oil insight/result fl ange and provision for temperature detectors conduction to the junction package. In the upper part there can be an inspection cover, checking the proper lubrication of meshing gears, a breather and provision for vibration probes. Split face of the casing can be 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 from one piece along with gearing. LS shaft and the gear are forged separately and the gear is high temperature assembled on the shaft. The backsplash band is usually forged in one piece with the shaft or heat assembled. Both gears are floor to high precision. The teeth fl anks of HS pinion have got special modifi cations to reduce the sound level and compensate the defl ection of shafts because of weighty load. A hunting tooth combination is present for mating gears when a tooth on the pinion does not repeat connection with a tooth on the gear wheel until it provides contacted the rest of the gear wheel tooth. The shape of shafts ends depends upon customer’s demand (cylindrical, tapered, fl anged etc.). Both shafts are dynamical balanced in accordance to ISO 1940 or API 613. 2.3.3 Bearings Solely hydrodynamic bearings with more sliding faces are used because of 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 moving
LS (low velocity) shaft is usually placed in simple journal bearings with cylindrical clearance (fi xed geometry). Among the bearings is certainly radial (on the non-traveling end) and the other one (on the driving end of 
the shaft) is mixed radialaxial bearing. The look 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 rate and pitchline velocity and both of these are radial bearings. Tilting pad bearings usually have four or five 5 pads and static load direction goes either on one pad or between pads. Lubrication of these bearings can be reached by overflowing the area between pads or essential oil injection between pads through a number of nozzles which also defends pads against circumferential motion. When oil injection is used it is possible to reduce friction losses significantly. These bearings have the best level of resistance against rotor instability because they do not generate any load leading to instability
2.5 Gearbox Testing 2 Item description and key features 3 Gearbox selection 1 Introduction 2 Item description and key features 2 Product description and key features 2.5.1 Load lab tests of high-speed gearboxes Testing laboratory for high-acceleration gearboxes is a camera monitored contemporary workplace at Ever-power manufacturing plant in Pilsen. The Powerful Test Bench is a tests facility equipped with a computer managed 1 MW electric motor with speed up to 3.600 rpm, managed load by a generator up to 710 kW of power, auxiliary gearboxes enabling testing of the main gearbox with speed up to 35.000 rpm. The test bench have 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 definitely supported with pneumatic pumps providing full volume of oil in case of power outage. The tests process is instantly recorded while oil and bearing temperature, pressure, noise, total and relative vibrations are measured and used in a control space for assessment by a specialized software.
