1.1 Company introduction 1.2 Application range of Ever-power high swiftness gearboxes Ever-power has been active in mechanical engineering for 25 years. For almost 25 years, we’ve been manufacturing gears and mechanical gearboxes. Our purpose is to keep delivering state-of-the-art products to your customers through intensive primary engineering and product development. We apply a maximally creative approach while addressing technical problems and specific needs of our customers. Our goal is constant development of items with a higher level of useful and quality parameters. We propose optimum solutions based on an intensive comprehension of every concrete software. We supply high-speed equipment units especially for thermal power station, heat plants, coal and oil sector or sugar refineries. High speed gearboxes are a crucial 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 acceleration 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 and also other instruments allow us to become maximally fast and versatile. Our team of design engineers cooperates with universities, research 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 models properties.
2.1 Item introduction High-speed 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 equipment and gearboxes are assembled using personal components or components supplied by European producers. All products undergo comprehensive testing on a dynamic test bench. The look and gear strength calculation are performed according to API 613 5th Edition and AGMA 6011*. Item types: RS and RU gearbox type is designed to endure forces from meshing of dual helical gears. They are not made to withstand any external axial or radial load. R1T and R2T gearbox type is designed to endure 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 can be through thrust collars. The gearbox is self supporting and doesn’t need any reinforcement. It has a foot flange for installation to a base and jack bolts (levelling bolts) for easy installation. The gearbox does not require any unique planetary gearbox maintenance. It is recommended to change the essential oil on regular basis or when changing the climate conditions – see the Operating Manual for details. Regular gearbox is altered for high speed procedure in the temperature range between -50 / +50°C provided the essential oil preheating at low temperatures and oil cooling at high temperatures. If the gearbox be managed in hazardous region or under other particular conditions, it needs to be contractually agreed. The standard gearbox efficiency is generally greater than 98,5%. Total efficiency depends on plenty of factors, such as 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 can be sized based on the transmitted power. Power is definitely given by a customer. It is not possible to lessen mesh losses considerably, nevertheless Ever-power aims to optimize the losses to attain the best compromise as well as gear life, durability and NVH behaviour. bearing losses these losses possess the biggest impact on the gearbox performance. It is necessary to design and size the bearing properly. windage losses windage losses have got big influence on the gearbox efficiency if the apparatus circumferential velocity is usually high. You’ll be able to reduce these losses (up to approx 50%) utilizing the windage cover. other losses gearbox efficiency can be 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 low case. It is fabricated steel construction. The housing is optimized by CAE methods to ensure once and for all stiffness, low sound emissions, excellent cooling properties and minimum weight. In the lower part there are foot for repairing the gearbox to the foundation equipped by jack bolts and with provision for installation of earthing screw (if the gearbox is determined to the hazardous area). Addititionally there is located the oil input/result fl ange and provision for temperature detectors conduction to the junction container. In the upper component there can be an inspection cover, examining the correct lubrication of meshing gears, a breather and provision for vibration probes. Split encounter of the casing is certainly 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 from 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 ring is usually forged in one piece with the shaft or warmth assembled. Both gears are floor 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 heavy load. A hunting tooth combination is present for mating gears whenever a tooth on the pinion will not repeat connection with a tooth on the gear wheel until it offers contacted the rest of the gear wheel teeth. The form of shafts ends depends on customer’s ask for (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 split into bearings with: • fi xed geometry – there is absolutely no movement of sliding faces • tilting pads – sliding faces are moving
LS (low speed) shaft is generally placed in plain 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 driving end of the shaft) is combined 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 because of high velocity and pitchline velocity and both of these are radial bearings. Tilting pad bearings usually have 4 or 5 5 pads and static load path goes either using one pad or between pads. Lubrication of the bearings can be reached by overflowing the space between pads or oil injection between pads by means of several nozzles which also defends pads against circumferential motion. When essential oil injection is used you’ll be able to reduce friction losses significantly. These bearings have the highest resistance against rotor instability because they do not 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 Product description and key features 2.5.1 Load assessments of high-speed gearboxes Testing laboratory for high-rate gearboxes is a camera monitored contemporary workplace at Ever-power manufacturing plant in Pilsen. The Dynamic Check Bench is a screening facility built with a computer managed 1 MW motor with increase 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 test bench have a lubrication centre 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 level of oil in the event of power outage. The examining process is automatically recorded while oil and bearing temperature, pressure, noise, total and relative vibrations are measured and used in a control area for assessment by a specialized software.