1.1 Company introduction 1.2 Application range of Ever-power high acceleration gearboxes Ever-power has been energetic in mechanical engineering for 25 years. For nearly 25 years, we’ve been manufacturing gears and mechanical gearboxes. Our purpose is to keep providing state-of-the-art products to our customers through intensive primary engineering and product development. We apply a maximally creative approach while addressing technical problems and specific needs of our clients. Our goal is constant development of items with a higher level of practical and quality parameters. We propose ideal solutions based on a thorough comprehension of each concrete software. We supply high-speed equipment units particularly for thermal power station, heat plants, coal and oil sector or sugars refineries. High acceleration gearboxes are a key 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 quickness applications since 1977. The worldwide installation foot of the parallel shaft gearboxes totals over 800 models. The calculation and design software KISSsoft and a 3D CAD program SOLID-EDGE along with other instruments enable us to end up being maximally fast and flexible. Our team of design engineers cooperates with universities, analysis institutes and leading specialists from all around the world. Ever-power uses state-of-the-art finite element method (FEM) software tools for identifying and optimizing gear units properties.
2.1 Item introduction High-acceleration gearboxes designed and manufactured 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 personal components or components given by European manufacturers. All products undergo thorough testing on a powerful test bench. The look 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 endure forces from meshing of double helical gears. They aren’t designed to withstand any exterior 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 is certainly by way of thrust collars. The gearbox can be self supporting and doesn’t need any reinforcement. It includes a foot flange for installation to a foundation and jack bolts (levelling bolts) for easy set up. The gearbox will not require any particular maintenance. It is suggested to change the oil on regular basis or when changing the climate conditions – start to see the Working Manual for details. Regular gearbox is modified for high speed operation in the temperature range between -50 / +50°C provided the oil preheating at low temperature ranges and essential oil cooling at high temps. Should the gearbox be operated in hazardous region or under other special conditions, it has to be contractually agreed. The typical gearbox efficiency is normally higher than 98,5%. Total efficiency depends on plenty of elements, such as mesh losses, bearing losses, planetary gearbox windage losses etc. Ever-power is competent to prepare customized solution to raise the gearbox effi ciency up to 99,5%. mesh losses gearing is usually sized predicated on the transmitted power. Power is certainly distributed by a customer. It is not possible to lessen mesh losses considerably, nevertheless Ever-power aims to enhance the losses to attain the best compromise as well as gear life, toughness and NVH behaviour. bearing losses these losses possess the biggest influence on the gearbox efficiency. It is necessary to create and size the bearing correctly. windage losses windage losses have big impact on the gearbox efficiency if the apparatus circumferential velocity is usually high. You’ll be able to decrease these losses (up to approx 50%) utilizing the windage cover. additional losses gearbox efficiency is also affected by the essential oil pump losses (if utilized), oil injection loss 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 consists of 2 parts: the upper and the lower case. It is fabricated steel construction. The housing can be optimized by CAE solutions to ensure for good stiffness, low noise emissions, excellent cooling properties and minimal weight. In the lower 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 determined to the hazardous area). Addititionally there is located the oil insight/result fl ange and provision for temperature detectors conduction to the junction container. In the upper component 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 can be 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 parts. HS shaft can be forged in one piece along with gearing. LS shaft and the apparatus are forged separately and the gear is temperature assembled on the shaft. The backsplash ring is usually forged in one piece with the shaft or high temperature assembled. Both gears are surface to high precision. Teeth fl anks of HS pinion have got special modifi cations to lessen the sound level and compensate the defl ection of shafts due to large load. A hunting tooth mixture is present for mating gears when a tooth on the pinion will not repeat contact with a tooth on the apparatus wheel until it provides contacted all the other gear wheel the teeth. The form of shafts ends depends upon customer’s request (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 an increase of 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 quickness) shaft is usually placed in simple journal bearings with cylindrical clearance (fi xed geometry). One of the bearings is definitely radial (on the non-traveling end) and the various other one (on the traveling end of the shaft) is combined radialaxial bearing. The look and calculation of the bearings are performed based on the latest strategies. Bearings on HS (high speed) shaft are usually tilting pad type because of high quickness and pitchline velocity and both of them are radial bearings. Tilting pad bearings will often have four or five 5 pads and static load direction goes either using one pad or between pads. Lubrication of these bearings can be reached by overflowing the space between pads or oil injection between pads through many nozzles which also defends pads against circumferential movement. When essential oil injection is used you’ll be able to reduce friction losses considerably. These bearings have the best resistance against rotor instability because they don’t generate any load leading to instability
2.5 Gearbox Testing 2 Product explanation and key features 3 Gearbox selection 1 Introduction 2 Product description and key features 2 Item description and key features 2.5.1 Load assessments of high-acceleration gearboxes Testing laboratory for high-quickness gearboxes is a camera monitored modern place of work at Ever-power manufacturing facility in Pilsen. The Dynamic Check Bench is a tests facility equipped with a computer managed 1 MW motor with increase to 3.600 rpm, managed load by a generator up to 710 kW of power, auxiliary gearboxes enabling testing of the primary gearbox with speed up to 35.000 rpm. The test bench have a lubrication centre with adjustable essential 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 backed up with pneumatic pumps supplying full level of oil in the event of power outage. The screening process is immediately recorded while oil and bearing temperature, pressure, noise, complete and relative vibrations are measured and transferred to a control area for evaluation by a specific software.