1.1 Company introduction 1.2 Application selection of Ever-power high rate gearboxes Ever-power has been active in mechanical engineering for 25 years. For almost 25 years, we’ve been production gears and mechanical gearboxes. Our purpose is to keep delivering 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 requirements of our clients. Our goal is continuous development of products with a higher degree of practical and quality parameters. We propose ideal solutions on the basis of a thorough comprehension of each concrete app. We supply high-speed gear units especially for thermal power station, heat plants, coal and oil sector or sugar refineries. High rate gearboxes are a essential component for applications such: • Turbogenerator drives • Steam and gas turbine drives • Turbocompressor drives • Pump drives • Test benches Ever-power has custom in high acceleration applications since 1977. The worldwide installation base of the parallel shaft gearboxes totals over 800 devices. The calculation and design software KISSsoft and a 3D CAD program SOLID-EDGE and also other instruments allow us to end up being maximally fast and versatile. Our team of design engineers cooperates with universities, analysis institutes and leading specialists from all over the world. Ever-power uses state-of-the-art finite component method (FEM) software tools for identifying and optimizing gear models properties.
2.1 Product introduction High-acceleration gearboxes designed and produced in Ever-power are designated primarily for power generation industry, compressor and pump applications. The manufacture is completed on the modern machine tools and gearboxes are assembled using very own components or components given by European planetary gearbox manufacturers. All products undergo thorough testing on a dynamic test bench. The design and gear power calculation are performed in accordance to API 613 5th Edition and AGMA 6011*. Item types: RS and RU gearbox type is designed to withstand forces from meshing of double helical gears. They are not designed to withstand any exterior axial or radial load. R1T and R2T gearbox type is made to withstand 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 is usually by means of thrust collars. The gearbox is usually self supporting and does not need any reinforcement. It includes a foot flange for installation 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 climate conditions – see the Operating Manual for details. Standard gearbox is modified for high speed procedure in the temperature range between -50 / +50°C provided the essential oil preheating at low temps and essential 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 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 boost the gearbox effi ciency up to 99,5%. mesh losses gearing can be sized predicated on the transmitted power. Power is certainly given by a customer. It is not possible to lessen mesh losses considerably, nevertheless Ever-power aims to improve the losses to achieve the best compromise together with gear life, toughness and NVH behaviour. bearing losses these losses possess the biggest influence on the gearbox effectiveness. It is necessary to create and size the bearing properly. windage losses windage losses have got big influence on the gearbox effectiveness if the gear circumferential velocity is usually high. It is possible to reduce these losses (up to approx 50%) by using the windage cover. additional losses gearbox efficiency can be affected by the oil pump losses (if used), oil injection reduction 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 really is fabricated steel construction. The housing is certainly optimized by CAE solutions to ensure for good stiffness, low noise emissions, superb cooling properties and minimum weight. In the lower part there are ft for repairing the gearbox to the foundation equipped by jack bolts and with provision for mounting of earthing screw (if the gearbox is determined to the hazardous region). Addititionally there is located the oil input/result fl ange and provision for temperature detectors conduction to the junction box. In the upper component there is an inspection cover, looking at the correct lubrication of meshing gears, a breather and provision for vibration probes. Split face of the casing is usually 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 items. HS shaft is definitely forged in one piece along with gearing. LS shaft and the apparatus are forged separately and the apparatus is high temperature assembled on the shaft. The backsplash band is usually forged from one piece with the shaft or warmth 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 due to large load. A hunting tooth combination is present for mating gears whenever a tooth on the pinion does not repeat contact with a tooth on the gear wheel until it provides contacted the rest of the gear wheel the teeth. The form of shafts ends depends upon customer’s ask for (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 split into bearings with: • fi xed geometry – there is no motion of sliding faces • tilting pads – sliding faces are moving
LS (low acceleration) shaft is normally placed in basic journal bearings with cylindrical clearance (fi xed geometry). One of the bearings is definitely radial (on the non-driving end) and the various other one (on the generating end of the shaft) is mixed radialaxial bearing. The look and calculation of the bearings are performed based on 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 usually have 4 or 5 5 pads and static load path goes either on one pad or between pads. Lubrication of these bearings could be reached by overflowing the space between pads or essential oil injection between pads by way of a number of nozzles which also defends pads against circumferential motion. When essential oil injection is used you’ll be able to decrease friction losses significantly. These bearings have the best resistance against rotor instability because they do not generate any load causing instability
2.5 Gearbox Testing 2 Product explanation and key features 3 Gearbox selection 1 Introduction 2 Item description and key features 2 Product description and key features 2.5.1 Load testing of high-acceleration gearboxes Testing laboratory for high-speed gearboxes is a camera monitored modern place of work at Ever-power manufacturing plant in Pilsen. The Powerful Test Bench is a testing facility built with a computer managed 1 MW electric motor with increase to 3.600 rpm, controlled 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 center with adjustable essential oil fl ow from 10 to at least one 1.600 liters/ minute, controllable oil temperature and water cooling up to 800 kW of power. The lubrication is supported with pneumatic pumps supplying full level of oil in case of power outage. The testing process is immediately recorded while essential oil and bearing temperature, pressure, noise, absolute and relative vibrations are measured and used in a control area for assessment by a specialized software.