1.1 Company introduction 1.2 Application selection of Ever-power high speed gearboxes Ever-power has been energetic in mechanical engineering for 25 years. For almost 25 years, we’ve been manufacturing gears and mechanical gearboxes. Our goal is to keep providing state-of-the-art products to your customers planetary gearbox through intensive core engineering and product advancement. We apply a maximally creative approach while addressing technical problems and specific requirements of our customers. Our goal is continuous development of products with a higher degree of functional and quality parameters. We propose ideal solutions based on an intensive comprehension of every concrete app. We supply high-speed gear units especially for thermal power station, heat plants, oil and gas sector or sugar refineries. High speed gearboxes are a important 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 models. The calculation and style software program 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, study institutes and leading specialists from all over the world. Ever-power uses state-of-the-art finite element method (FEM) software tools for identifying and optimizing gear products properties.
2.1 Item introduction High-rate gearboxes designed and produced in Ever-power are designated mainly 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 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 made to withstand 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 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 definitely by means of thrust collars. The gearbox is definitely self supporting and doesn’t need any reinforcement. It has a foot flange for installation to a foundation and jack bolts (levelling bolts) for easy set up. The gearbox does not require any special maintenance. It is recommended to change the oil on regular basis or when changing the weather conditions – 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 temps and essential oil cooling at high temperatures. If the gearbox be operated in hazardous region or under other special conditions, it has to be contractually agreed. The typical gearbox efficiency is normally greater than 98,5%. Total efficiency depends on plenty of factors, such as mesh losses, bearing losses, windage losses etc. Ever-power is capable to prepare customized solution to raise the gearbox effi ciency up to 99,5%. mesh losses gearing is 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 optimize the losses to attain the best compromise together with gear life, durability and NVH behaviour. bearing losses these losses possess the biggest impact on the gearbox efficiency. It is necessary to design and size the bearing properly. windage losses windage losses have big influence on the gearbox efficiency 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 can be affected by the essential 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 contains 2 parts: the upper and the lower case. It is fabricated steel construction. The housing is optimized by CAE methods to ensure for good stiffness, low noise emissions, exceptional cooling properties and minimum weight. In the low part there are foot for repairing the gearbox to the building blocks equipped by jack bolts and with provision for mounting of earthing screw (if the gearbox is set to the hazardous region). Addititionally there is located the oil input/result fl ange and provision for temperature detectors conduction to the junction package. 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 certainly 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 definitely forged from one piece along with gearing. LS shaft and the apparatus are forged separately and the gear is heat assembled on the shaft. The backsplash ring is usually forged in one piece with the shaft or warmth assembled. Both gears are ground to high precision. Tooth fl anks of HS pinion possess special modifi cations to reduce the noise level and compensate the defl ection of shafts because of weighty load. A hunting tooth mixture is present for mating gears whenever a tooth on the pinion does not repeat connection with a tooth on the apparatus wheel until it offers contacted the rest of the gear wheel the teeth. The form of shafts ends depends on 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 no movement of sliding faces • tilting pads – sliding faces are moving
LS (low rate) shaft is usually placed in plain journal bearings with cylindrical clearance (fi xed geometry). Among the bearings is definitely radial (on the non-traveling end) and the additional 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 velocity 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 on one pad or between pads. Lubrication of these bearings can be reached by overflowing the area between pads or oil injection between pads by way of many nozzles which also protects pads against circumferential movement. When essential oil injection is used you’ll be able to decrease friction losses significantly. These bearings possess the best level of resistance against rotor instability because they do not generate any load leading to instability
2.5 Gearbox Testing 2 Product description and key features 3 Gearbox selection 1 Introduction 2 Product explanation and key features 2 Item explanation and key features 2.5.1 Load testing of high-speed gearboxes Testing laboratory for high-rate gearboxes is a camera monitored modern place of work at Ever-power manufacturing facility in Pilsen. The Powerful Test Bench is a tests facility built 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 allowing testing of the main gearbox with increase to 35.000 rpm. The test bench have a lubrication center with adjustable 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 definitely supported with pneumatic pumps supplying full level of oil in the event of power outage. The assessment process is automatically recorded while essential oil and bearing temperature, pressure, noise, complete and relative vibrations are measured and used in a control room for assessment by a specialized software.