Speed gearbox

1.1 Company introduction 1.2 Application range of Ever-power high rate gearboxes Ever-power has been active in mechanical engineering for 25 years. For almost 25 years, we have been manufacturing 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 innovative approach while addressing technical problems and specific requirements of our customers. Our goal is constant development of items with a higher level of useful and quality parameters. We propose optimal solutions based on a thorough comprehension of every concrete application. We supply high-speed equipment units particularly for thermal power station, heat plants, coal and oil sector or sugar refineries. High swiftness gearboxes are a essential component for applications this kind of: • Turbogenerator drives • Steam and gas turbine drives • Turbocompressor drives • Pump drives • Test benches Ever-power has tradition in high speed applications since 1977. The worldwide installation base of the parallel shaft gearboxes totals over 800 systems. The calculation and style software KISSsoft and a 3D CAD program SOLID-EDGE along with other instruments enable 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 globe. Ever-power uses state-of-the-art finite component method (FEM) software equipment for identifying and optimizing gear products properties.
2.1 Product introduction High-velocity gearboxes designed and manufactured in Ever-power are designated mainly for power generation industry, compressor and pump applications. The manufacture is carried out on the modern machine tools and gearboxes are assembled using personal components or components given by European manufacturers. All products undergo comprehensive planetary gearbox 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 aren't made to withstand any external 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 is by way of thrust collars. The gearbox is usually 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 installation. The gearbox will not require any unique maintenance. It is suggested to change the essential oil on regular basis or when changing the climate conditions - start to see the Operating Manual for details. Regular gearbox is altered for high speed operation in the temperature range between -50 / +50°C provided the oil preheating at low temperature ranges 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 usually higher than 98,5%. Total efficiency depends on plenty of factors, such as for example mesh losses, bearing losses, windage losses etc. Ever-power is competent to prepare personalized solution to raise the gearbox effi ciency up to 99,5%. mesh losses gearing is certainly sized based on the transmitted power. Power is definitely distributed by a customer. It is not possible to lessen mesh losses considerably, however Ever-power aims to improve the losses to attain the best compromise as well as gear life, strength and NVH behaviour. bearing losses these losses have the biggest impact on the gearbox effectiveness. It is necessary to design and size the bearing correctly. windage losses windage losses have got big influence on the gearbox performance if the apparatus circumferential velocity is high. It is possible 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 used), 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 low case. It is fabricated steel structure. The housing is optimized by CAE solutions to ensure once and for all stiffness, low sound emissions, excellent cooling properties and minimal weight. In the lower part there are foot for fixing the gearbox to the foundation equipped by jack bolts and with provision for mounting of earthing screw (if the gearbox is set to the hazardous area). There is also located the oil input/output fl ange and provision for temperature detectors conduction to the junction container. 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 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 items. HS shaft is forged in one piece along with gearing. LS shaft and the apparatus are forged separately and the apparatus is heat 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. 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 large load. A hunting tooth combination is present for mating gears when a tooth on the pinion does not repeat contact with a tooth on the apparatus wheel until it has contacted all the other gear wheel the teeth. The shape of shafts ends depends on customer’s request (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 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 no motion of sliding faces • tilting pads - sliding faces are moving
LS (low velocity) shaft is generally placed in plain journal bearings with cylindrical clearance (fi xed geometry). Among the bearings is radial (on the non-driving end) and the other one (on the generating end of the shaft) is mixed radialaxial bearing. The design and calculation of the bearings are performed according to the latest strategies. Bearings on HS (high speed) shaft are usually tilting pad type due to high acceleration and pitchline velocity and both of these are radial bearings. Tilting pad bearings will often have 4 or 5 5 pads and static load direction goes either on one pad or between pads. Lubrication of the 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 protects pads against circumferential movement. When essential oil injection is used you'll be able to decrease friction losses substantially. These bearings have the highest resistance against rotor instability because they do not generate any load causing instability
2.5 Gearbox Testing 2 Item description and key features 3 Gearbox selection 1 Introduction 2 Item description and key features 2 Item description and key features 2.5.1 Load assessments of high-velocity gearboxes Testing laboratory for high-speed gearboxes is a camera monitored contemporary workplace at Ever-power manufacturing facility in Pilsen. The Dynamic Test Bench is a testing facility built with a computer controlled 1 MW 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 check bench have a lubrication center 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 backed up with pneumatic pumps providing full volume of oil in the event of power outage. The screening process is automatically recorded while oil and bearing temperature, pressure, noise, complete and relative vibrations are measured and transferred to a control area for assessment by a specific software.