1.1 Company introduction 1.2 Application selection of Ever-power high quickness gearboxes Ever-power has been active in mechanical engineering for 25 years. For nearly 25 years, we have been production gears and mechanical gearboxes. Our purpose is to keep providing state-of-the-art products to your customers through intensive primary engineering and product advancement. We apply a maximally creative approach while addressing specialized problems and specific needs of our customers. Our goal is constant development of items with a higher degree of useful and quality parameters. We propose optimum solutions on the basis of a thorough comprehension of every concrete application. We supply high-speed equipment units especially for thermal power station, heat plants, oil and gas sector or glucose 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 quickness applications since 1977. The worldwide installation foot of the planetary gearbox parallel shaft gearboxes totals over 800 models. The calculation and style software KISSsoft and a 3D CAD program SOLID-EDGE along with other instruments allow us to become maximally fast and versatile. Our team of style engineers cooperates with universities, study institutes and leading specialists from all over the globe. Ever-power uses state-of-the-artwork finite element method (FEM) software tools for determining and optimizing gear systems properties.
2.1 Product introduction High-velocity gearboxes designed and manufactured in Ever-power are designated primarily for power generation industry, compressor and pump applications. The manufacture is completed on the present day machine tools and gearboxes are assembled using own components or components supplied by European producers. All products undergo comprehensive testing on a dynamic test bench. The design and gear power calculation are performed according to API 613 5th Edition and AGMA 6011*. Product types: RS and RU gearbox type is made to withstand forces from meshing of dual helical gears. They are not designed to withstand any external axial or radial load. R1T and R2T gearbox type is designed to endure forces from meshing of one helical gears and exterior axial and radial load. The transmission of exterior axial load from HS shaft to LS shaft can be through thrust collars. The gearbox is self supporting and does not need any reinforcement. It has a foot flange for mounting to a basis and jack bolts (levelling bolts) for easy set up. The gearbox will not require any unique maintenance. It is recommended to change the oil on regular basis or when changing the weather conditions – start to see the Operating Manual for details. Standard gearbox is adjusted for high speed procedure in the temperature range between -50 / +50°C provided the oil preheating at low temperature ranges and essential oil cooling at high temperatures. Should the gearbox be managed in hazardous area or under other unique conditions, it has to be contractually agreed. The typical gearbox efficiency is normally higher than 98,5%. Total efficiency depends upon plenty of factors, such as mesh losses, bearing losses, windage losses etc. Ever-power is capable to prepare customized solution to boost the gearbox effi ciency up to 99,5%. mesh losses gearing is usually sized based on the transmitted power. Power is definitely given by a customer. It isn’t possible to reduce mesh losses considerably, however Ever-power aims to enhance the losses to achieve the best compromise as well as gear life, durability and NVH behaviour. bearing losses these losses have the biggest impact on the gearbox effectiveness. It is necessary to design and size the bearing properly. windage losses windage losses have got big impact on the gearbox performance if the gear circumferential velocity is high. It is possible to reduce these losses (up to approx 50%) by using the windage cover. various other losses gearbox efficiency is also 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 includes 2 parts: the upper and the lower case. It is fabricated steel construction. The housing is definitely optimized by CAE methods to ensure once and for all stiffness, low sound emissions, excellent cooling properties and minimum weight. In the lower part there are feet for fixing the gearbox to the foundation outfitted by jack bolts and with provision for mounting of earthing screw (if the gearbox is determined to the hazardous area). There is also located the oil insight/result fl ange and provision for temperature detectors conduction to the junction container. In the upper part there can be an inspection cover, looking at the correct lubrication of meshing gears, a breather and provision for vibration probes. Split face of the casing is definitely horizontal, parallel to shaft axis. Both parts are connected by bolts and fi xed by dowel pins. 2.3.2 Shafts and gears Both shafts are forged pieces. HS shaft is forged from one piece along with gearing. LS shaft and the gear are forged separately and the apparatus is temperature assembled on the shaft. The backsplash band is usually forged in one piece with the shaft or high temperature assembled. Both gears are ground to high precision. Teeth fl anks of HS pinion possess special modifi cations to lessen the sound level and compensate the defl ection of shafts because of weighty load. A hunting tooth combination is present for mating gears whenever a tooth on the pinion will not repeat connection with a tooth on the gear wheel until it has contacted the rest of the gear wheel tooth. The form of shafts ends depends upon customer’s ask for (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 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 moving
LS (low speed) shaft is generally placed in basic journal bearings with cylindrical clearance (fi xed geometry). Among the bearings is usually radial (on the non-generating end) and the additional 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 strategies. Bearings on HS (high speed) shaft are often tilting pad type due to high swiftness and pitchline velocity and both of these are radial bearings. Tilting pad bearings will often have four or five 5 pads and static load direction goes either on one pad or between pads. Lubrication of the bearings can be reached by overflowing the space between pads or essential oil injection between pads by means of a number of nozzles which also protects pads against circumferential movement. When essential oil injection is used you’ll be able to decrease friction losses substantially. These bearings possess the best resistance against rotor instability because they don’t generate any load causing instability
2.5 Gearbox Testing 2 Product description and key features 3 Gearbox selection 1 Introduction 2 Product description and key features 2 Item description and key features 2.5.1 Load tests of high-velocity gearboxes Testing laboratory for high-rate gearboxes is a camera monitored modern place of work at Ever-power manufacturing plant in Pilsen. The Powerful Check Bench is a screening facility equipped with a computer controlled 1 MW engine with increase to 3.600 rpm, managed load by a generator up to 710 kW of power, auxiliary gearboxes allowing testing of the primary gearbox with increase to 35.000 rpm. The test 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 can be supported with pneumatic pumps providing full level 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 room for evaluation by a specific software.