1.1 Company introduction 1.2 Application selection of Ever-power high swiftness gearboxes Ever-power has been energetic in mechanical engineering for 25 years. For nearly 25 years, we have been manufacturing gears and mechanical gearboxes. Our aim is to keep delivering state-of-the-art products to your customers through intensive primary engineering and product development. We apply a maximally innovative approach while addressing specialized problems and specific requirements of our customers. Our goal is constant development of products with a higher level of useful and quality parameters. We propose optimum solutions based on an intensive comprehension of every concrete application. We supply high-speed equipment units particularly for thermal power station, heat plants, oil and gas sector or sugars refineries. High rate gearboxes are a key 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 devices. The calculation and style software KISSsoft and a 3D CAD program SOLID-EDGE and also other instruments enable us to end up being maximally fast and flexible. Our team of style engineers cooperates with universities, research institutes and leading professionals from all around the globe. Ever-power uses state-of-the-art finite component method (FEM) software tools for identifying and optimizing gear products properties.
2.1 Item introduction High-quickness gearboxes designed and manufactured in Ever-power are designated primarily for power generation industry, compressor and pump applications. The manufacture is completed 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 look and gear power calculation are performed according to API 613 5th Edition and AGMA 6011*. Item types: RS and RU gearbox type is designed to planetary gearbox withstand forces from meshing of double helical gears. They are not designed to withstand any external axial or radial load. R1T and R2T gearbox type is designed to withstand forces from meshing of one helical gears and external axial and radial load. The transmission of external axial load from HS shaft to LS shaft is definitely by way of thrust collars. The gearbox is definitely self supporting and does not need any reinforcement. It includes a foot flange for mounting to a base and jack bolts (levelling bolts) for easy set up. The gearbox will not require any special 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. Standard 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 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 generally higher than 98,5%. Total efficiency depends on plenty of elements, such as for example mesh losses, bearing losses, windage losses etc. Ever-power is capable to prepare personalized solution to raise the gearbox effi ciency up to 99,5%. mesh losses gearing is sized predicated on the transmitted power. Power is distributed by a customer. It isn’t possible to lessen mesh losses considerably, nevertheless Ever-power aims to optimize the losses to attain the best compromise together with gear life, strength and NVH behaviour. bearing losses these losses have the biggest impact on the gearbox performance. It is necessary to design and size the bearing properly. windage losses windage losses have big impact on the gearbox performance if the apparatus circumferential velocity can be high. You’ll be able to reduce these losses (up to approx 50%) by using the windage cover. additional losses gearbox efficiency is also affected by the essential oil pump losses (if used), oil injection reduction 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 contains 2 parts: the upper and the low case. It is fabricated steel building. The housing is usually optimized by CAE solutions to ensure once and for all stiffness, low sound emissions, excellent cooling properties and minimal weight. In the low part there are foot for fixing the gearbox to the building blocks outfitted by jack bolts and with provision for installation of earthing screw (if the gearbox is determined to the hazardous region). There is also 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 proper lubrication of meshing gears, a breather and provision for vibration probes. Split encounter of the casing can be 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 parts. HS shaft is certainly forged from one piece along with gearing. LS shaft and the apparatus are forged separately and the gear is warmth assembled on the shaft. The backsplash ring is usually forged in one piece with the shaft or temperature assembled. Both gears are surface to high precision. Teeth fl anks of HS pinion have special modifi cations to reduce the sound level and compensate the defl ection of shafts because of heavy load. A hunting tooth combination is present for mating gears when a tooth on the pinion will not repeat contact with a tooth on the gear wheel until it provides contacted all the other gear wheel teeth. The form of shafts ends depends on customer’s demand (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 due to high speeds and bearing load. These bearings are split into bearings with: • fi xed geometry – there is absolutely no motion of sliding faces • tilting pads – sliding faces are moving
LS (low speed) shaft is usually placed in ordinary journal bearings with cylindrical clearance (fi xed geometry). One of the bearings can be radial (on the non-traveling 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 based on the latest strategies. Bearings on HS (high speed) shaft are usually tilting pad type due to high swiftness 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 the bearings can be reached by overflowing the area between pads or oil injection between pads through many nozzles which also protects pads against circumferential motion. When oil injection is used you’ll be able to reduce friction losses considerably. These bearings possess the highest level of resistance against rotor instability because they do not generate any load causing instability
2.5 Gearbox Testing 2 Item explanation and key features 3 Gearbox selection 1 Introduction 2 Product explanation and key features 2 Product explanation and key features 2.5.1 Load lab tests of high-quickness gearboxes Testing laboratory for high-rate gearboxes is a camera monitored modern workplace at Ever-power manufacturing plant in Pilsen. The Powerful Check Bench is a tests facility equipped with a computer controlled 1 MW engine with speed up to 3.600 rpm, controlled load by a generator up to 710 kW of power, auxiliary gearboxes allowing testing of the primary gearbox with speed up to 35.000 rpm. The check bench possess 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 usually backed up with pneumatic pumps providing full level of oil in the event of power outage. The tests process is automatically recorded while oil and bearing temperature, pressure, noise, complete and relative vibrations are measured and transferred to a control room for evaluation by a specialized software.