1.1 Company introduction 1.2 Application selection of Ever-power high acceleration gearboxes Ever-power has been energetic in mechanical engineering for 25 years. For almost 25 years, we’ve been production gears and mechanical gearboxes. Our aim is to keep delivering state-of-the-art products to our customers through intensive core engineering and product development. 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 level of functional and quality parameters. We propose optimum solutions based on an intensive comprehension of every concrete program. We supply high-speed equipment units especially for thermal power station, heat plants, coal and oil sector or sugars refineries. High swiftness gearboxes are a important 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 base of the parallel shaft gearboxes totals over 800 products. The calculation and design software program KISSsoft and a 3D CAD program SOLID-EDGE along with other instruments allow us to be maximally fast and versatile. Our team of style engineers cooperates with universities, study institutes and leading experts from all over the world. Ever-power uses state-of-the-artwork finite component method (FEM) software tools for determining and optimizing gear models properties.
2.1 Item introduction High-quickness gearboxes designed and produced in Ever-power are designated primarily for power generation industry, compressor and pump applications. The manufacture is carried out on the present day machine equipment 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 strength calculation are performed in accordance to API 613 5th Edition and AGMA 6011*. Item types: RS and RU gearbox type is made to endure forces from meshing of dual helical gears. They aren’t made to withstand any exterior axial or radial load. R1T and R2T gearbox type is designed to endure forces from meshing of solitary helical gears and exterior axial and radial load. The transmission of exterior axial load from HS shaft to LS shaft can be by way of thrust collars. The gearbox is 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 set up. The gearbox does not require any particular maintenance. It is suggested to change the essential 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 temps and oil cooling at high temps. Should the gearbox be operated in hazardous region or under other special conditions, it needs 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 increase the gearbox effi ciency up to 99,5%. mesh losses gearing is definitely 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 enhance the losses to achieve the best compromise together with gear life, durability and NVH behaviour. bearing losses these losses have the biggest impact on the gearbox performance. It is necessary to create and size the bearing properly. windage losses windage losses have big influence on the gearbox efficiency if the gear circumferential velocity is certainly high. You’ll be able to decrease these losses (up to approx 50%) by using the windage cover. various other losses gearbox efficiency can be affected by the essential oil pump losses (if used), oil injection loss etc.
2.3 Key specialized planetary gearbox 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 low case. It really is fabricated steel construction. The housing is optimized by CAE solutions to ensure for good stiffness, low noise emissions, excellent cooling properties and minimum weight. In the lower part there are feet for fixing the gearbox to the building blocks outfitted by jack bolts and with provision for mounting of earthing screw (if the gearbox is set to the hazardous region). There is also located the oil insight/output fl ange and provision for temperature detectors conduction to the junction container. In the upper component there is an inspection cover, checking the proper lubrication of meshing gears, a breather and provision for vibration probes. Split encounter 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 parts. HS shaft is 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 temperature assembled. Both gears are floor to high precision. The teeth fl anks of HS pinion have special modifi cations to lessen the noise level and compensate the defl ection of shafts because of heavy load. A hunting tooth mixture is present for mating gears whenever a tooth on the pinion will not repeat contact with a tooth on the gear wheel until it offers contacted all the other gear wheel tooth. The shape 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 more 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 velocity) shaft is normally placed in plain journal bearings with cylindrical clearance (fi xed geometry). Among the bearings is definitely radial (on the non-driving end) and the other one (on the generating end of the shaft) is combined radialaxial bearing. The design and calculation of the bearings are performed based on the latest strategies. Bearings on HS (high speed) shaft are usually tilting pad type due to high velocity and pitchline velocity and both of these are radial bearings. Tilting pad bearings usually have four or five 5 pads and static load path goes either on one pad or between pads. Lubrication of these bearings can be reached by overflowing the space between pads or oil injection between pads through several nozzles which also shields pads against circumferential movement. When essential oil injection is used you’ll be able to reduce friction losses substantially. These bearings possess the best level of resistance against rotor instability because they don’t generate any load causing instability
2.5 Gearbox Testing 2 Item explanation and key features 3 Gearbox selection 1 Introduction 2 Item explanation and key features 2 Product description and key features 2.5.1 Load exams of high-quickness gearboxes Testing laboratory for high-rate gearboxes is a camera monitored contemporary place of work at Ever-power manufacturing plant in Pilsen. The Powerful Check Bench is a assessment facility built with a computer managed 1 MW electric motor with speed up to 3.600 rpm, controlled 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 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 backed up 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 area for evaluation by a specific software.