Speed gearbox

1.1 Company introduction 1.2 Application selection of Ever-power high speed gearboxes Ever-power has been active in mechanical engineering for 25 years. For nearly 25 years, we have been manufacturing gears and mechanical gearboxes. Our purpose is to keep delivering state-of-the-art products to your customers through intensive core engineering and product development. We apply a maximally creative approach while addressing technical problems and specific requirements of our clients. Our goal is continuous development of items with a higher degree of practical and quality parameters. We propose ideal solutions based on a thorough comprehension of every concrete software. We supply high-speed equipment units especially for thermal power station, heat plants, coal and oil sector or glucose refineries. High velocity gearboxes are a crucial component for applications such: • Turbogenerator drives • Steam and gas turbine drives • Turbocompressor drives • Pump drives • Test benches Ever-power has tradition in high swiftness applications since 1977. The worldwide installation foot of the parallel shaft gearboxes totals over 800 units. The calculation and style software program KISSsoft and a 3D CAD program SOLID-EDGE along with other instruments enable us to become maximally fast and versatile. Our team of style engineers cooperates with universities, study institutes and leading experts from all around the world. Ever-power uses state-of-the-artwork finite component method (FEM) software equipment for identifying and optimizing gear products properties.
2.1 Product introduction High-acceleration gearboxes designed and produced 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 very own components or components supplied by European manufacturers. All products undergo thorough testing on a dynamic test bench. The look and gear power calculation are performed according to API 613 5th Edition and AGMA 6011*. Product types: RS and RU gearbox type is designed to endure forces from meshing of dual helical gears. They are not designed to withstand any exterior axial or radial load. R1T and R2T gearbox type is designed to withstand forces from meshing of solitary helical gears and external axial and radial load. The transmission of exterior axial load from HS shaft to LS shaft is by means of thrust collars. The gearbox is self supporting and does not need any reinforcement. It includes a foot flange for installation to a base and jack bolts (levelling bolts) for easy set up. The gearbox will not require any particular maintenance. It is recommended to change the oil on regular basis or when changing the climate conditions – see the Working 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 temperatures and oil cooling at high temperatures. Should the gearbox be operated in hazardous area or under other particular conditions, it has to be contractually agreed. The typical gearbox efficiency is normally higher than 98,5%. Total efficiency depends on plenty of elements, such as mesh losses, bearing losses, windage losses etc. Ever-power is competent to prepare customized solution to boost the gearbox effi ciency up to 99,5%. mesh losses gearing is certainly sized based on the transmitted power. Power is certainly given by a customer. It is not possible to reduce mesh losses considerably, however Ever-power aims to enhance the losses to achieve the best compromise together with gear life, toughness and NVH behaviour. bearing losses these losses have the biggest planetary gearbox impact on the gearbox efficiency. It is necessary to design and size the bearing properly. windage losses windage losses possess big impact on the gearbox efficiency if the gear circumferential velocity is definitely high. You’ll be able to reduce 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 technical 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 lower case. It is fabricated steel construction. The housing is usually optimized by CAE solutions to ensure for good stiffness, low noise emissions, superb cooling properties and minimum weight. In the lower part there are feet for repairing the gearbox to the foundation outfitted 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/output fl ange and provision for temperature detectors conduction to the junction package. In the upper component there is an inspection cover, checking the proper 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 parts. HS shaft is definitely forged in one piece along with gearing. LS shaft and the gear are forged separately and the apparatus is warmth assembled on the shaft. The backsplash band is usually forged from one piece with the shaft or heat assembled. Both gears are ground to high precision. Tooth fl anks of HS pinion possess special modifi cations to lessen the sound level and compensate the defl ection of shafts because of large load. A hunting tooth mixture exists for mating gears when a tooth on the pinion does not repeat connection with a tooth on the apparatus wheel until it provides contacted all the other gear wheel teeth. The form of shafts ends depends upon 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 due to high speeds and bearing load. These bearings are divided into bearings with: • fi xed geometry – there is absolutely no motion of sliding faces • tilting pads – sliding faces are moving
LS (low acceleration) shaft is generally placed in basic journal bearings with cylindrical clearance (fi xed geometry). One of the bearings is radial (on the non-driving end) and the various other one (on the traveling 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 because of high rate 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 essential oil injection between pads by way of a number of nozzles which also shields pads against circumferential movement. When essential oil injection is used it is possible to reduce friction losses substantially. These bearings have the best resistance against rotor instability because they do not generate any load leading to instability
2.5 Gearbox Testing 2 Item explanation and key features 3 Gearbox selection 1 Introduction 2 Product explanation and key features 2 Item description and key features 2.5.1 Load testing of high-speed gearboxes Testing laboratory for high-velocity gearboxes is a camera monitored modern workplace at Ever-power manufacturing plant in Pilsen. The Powerful Test Bench is a testing facility equipped with a computer controlled 1 MW engine with increase to 3.600 rpm, controlled load by a generator up to 710 kW of power, auxiliary gearboxes allowing testing of the main gearbox with speed up to 35.000 rpm. The test bench have 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 certainly supported with pneumatic pumps providing full volume of oil in the event of power outage. The screening process is instantly recorded while oil and bearing temperature, pressure, noise, total and relative vibrations are measured and used in a control area for evaluation by a specialized software.