Speed gearbox

1.1 Company introduction 1.2 Application range of Ever-power high rate gearboxes Ever-power has been active in mechanical engineering for 25 years. For almost 25 years, we have 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 needs of our customers. Our goal is constant development of items with a higher degree of functional and quality parameters. We propose ideal solutions based on a thorough comprehension of each concrete application. We supply high-speed gear units especially for thermal power station, heat plants, coal and oil sector or sugar refineries. High velocity 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 speed applications since 1977. The worldwide installation foot of the parallel shaft gearboxes totals over 800 systems. The calculation and design software KISSsoft and a 3D CAD program SOLID-EDGE and also other instruments allow us to end up being maximally fast and versatile. Our team of style engineers cooperates with universities, analysis institutes and leading professionals from all around the globe. 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-acceleration gearboxes designed and manufactured 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 personal components or components supplied by European producers. All products undergo comprehensive testing on a powerful test bench. The design and gear power calculation are performed in accordance to API 613 5th Edition and AGMA 6011*. Item types: RS and RU gearbox type is designed to endure forces from meshing of double planetary gearbox helical gears. They are not made to withstand any external axial or radial load. R1T and R2T gearbox type is made 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 can be by way of thrust collars. The gearbox is certainly 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 installation. The gearbox does not require any special maintenance. It is suggested to change the essential oil on regular basis or when changing the climate conditions – see the Operating 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 temperature ranges and oil cooling at high temperatures. Should the gearbox be operated in hazardous region or under other special conditions, it has to be contractually agreed. The standard gearbox efficiency is usually greater than 98,5%. Total efficiency depends upon plenty of elements, 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 is sized based on the transmitted power. Power is certainly given by a customer. It isn’t possible to lessen mesh losses considerably, however Ever-power aims to improve the losses to attain the best compromise together with gear life, strength and NVH behaviour. bearing losses these losses possess the biggest influence on the gearbox efficiency. It is necessary to create and size the bearing properly. windage losses windage losses possess big impact on the gearbox efficiency if the gear circumferential velocity is definitely high. It is possible to reduce these losses (up to approx 50%) by using the windage cover. additional losses gearbox efficiency can be affected by the 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 usually optimized by CAE methods to ensure for good stiffness, low sound emissions, exceptional cooling properties and minimum weight. In the lower part there are ft for repairing the gearbox to the foundation outfitted by jack bolts and with provision for mounting of earthing screw (if the gearbox is set to the hazardous area). There is also located the oil insight/result fl ange and provision for temperature detectors conduction to the junction package. In the upper part 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 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 pieces. HS shaft is definitely forged in 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 due to heavy load. A hunting tooth combination exists for mating gears when a tooth on the pinion does not repeat contact with a tooth on the apparatus wheel until it provides contacted all the other gear wheel tooth. The form of shafts ends depends on customer’s demand (cylindrical, tapered, fl anged etc.). Both shafts are dynamical balanced according 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 divided into bearings with: • fi xed geometry – there is no movement of sliding faces • tilting pads – sliding faces are moving
LS (low speed) shaft is generally placed in simple journal bearings with cylindrical clearance (fi xed geometry). Among the bearings is definitely radial (on the non-traveling end) and the various other 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 often tilting pad type because of high velocity and pitchline velocity and both of these 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 oil injection is used it is possible to reduce friction losses significantly. These bearings have the highest resistance against rotor instability because they do not generate any load causing instability
2.5 Gearbox Testing 2 Product explanation and key features 3 Gearbox selection 1 Introduction 2 Product explanation and key features 2 Item explanation and key features 2.5.1 Load assessments of high-swiftness gearboxes Testing laboratory for high-acceleration gearboxes is a camera monitored modern place of work at Ever-power manufacturing facility in Pilsen. The Dynamic Test Bench is a screening facility built with a computer controlled 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 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 can be supported with pneumatic pumps supplying full volume of oil in the event of power outage. The testing process is immediately recorded while oil and bearing temperature, pressure, noise, absolute and relative vibrations are measured and used in a control area for assessment by a specialized software.