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Articles About gearbox
Although a comprehensive on-site gearbox inspection is desirable in many situations, there may be constraints that limit the extent of the inspection such as cost, time, accessibility and qualified personnel. This article describes the equipment and techniques necessary to perform an on-site gearbox inspection.
Industrial gear standards have been used to support reliability through the specification of requirements for design, manufacturing and verification. The consensus development of an international wind turbine gearbox standard is an example where gear products can be used in reliable mechanical systems today. This has been achieved through progressive changes in gear technology, gear design methods and the continual development and refinement of gearbox standards.
Romax Technology, the gearbox, bearing and driveline engineering specialist, has launched a new design software package that will increase speed, quality, creativity and innovation when designing gearboxes and drivelines. Called Concept, the new product delivers on the Romax vision of streamlining the end-to-end, planning-to-manufacture process with open, easy to use software solutions. It has been developed in close collaboration with engineers in the largest ground vehicle, wind energy and industrial equipment companies around the globe.
Question: In the January/February issue of your magazine, we came across the term "electronic gearbox." We have seen this term used elsewhere as well. We understand that this EGB eliminates the change gear in the transmission line, but not how exactly this is done. Could you explain in more detail?
This method of testing large gearboxes or, indeed, any power transmission element, had numerous advantages and offers the possibility of large savings in time, energy, and plant, if the overall situation is conducive to its use. This usually requires that several such units need to be tested, and that they can be conveniently connected to each to each other in such a way as to form a closed-loop drive train. No power sink is required, and the drive input system has only to make up power losses. The level of circulating power is controlled by the torque, which is applied statically during rotation, and the drive speed. Principles, advantage, and limitations are described, together with recent experiences in the only known large-scale usage of this technique in Australia.
This paper presents an approach that provides optimization of both gearbox kinematic arrangement and gear tooth geometry to achieve a high-density gear transmission. It introduces dimensionless gearbox volume functions that can be minimized by the internal gear ratio optimization. Different gearbox arrangements are analyzed to define a minimum of the volume functions. Application of asymmetric gear tooth profiles for power density maximization is also considered.
Historically, wind turbine gearbox failures have plagued the industry. Yet an effective oil analysis program will increase the reliability and availability of your machinery, while minimizing maintenance costs associated with oil change-outs, labor, repairs and downtime. Practical action steps are presented here to improve reliability.
The wind turbine industry has been plagued with gearbox failures, which cause repair costs, legal expenses, lost energy production and environmental pollution.
Forensics isn't just for tough-talking, crime-busting scientists--most commonly found on your television; the tactic also holds the key to successful gearbox design and manufacture.
Gearbox performance, reliability, total cost of ownership (energy cost), overall impact on the environment, and anticipation of additional future regulations are top-of-mind issues in the industry. Optimization of the bearing set can significantly improve gearbox performance.
This article describes some of the most important tests for prototypes conducted at Winergy AG during the product development process. It will demonstrate that the measurement results on the test rig for load distribution are in accordance with the turbine measurements.
Most research on micropitting is done on small-sized gears. This article examines whether those results are also applicable to larger gears.
Having outlasted the worldwide Great Recession, the Global Wind Energy Council (GWEC) forecasts a constant growth in wind energy, i.e.: "increase in worldwide capacity to 460,000 MW by 2015."
If a gear system is run continuously for long periods of time—or if the starting loads are very low and within the normal operating spectrum—the effect of the start-up conditions may often be insignificant in the determination of the life of the gear system. Conversely, if the starting load is significantly higher than any of the normal operating conditions, and the gear system is started and stopped frequently, the start-up load may, depending on its magnitude and frequency, actually be the overriding, limiting design condition.
Although typically considered a late bloomer in the call to wind energy arms, the United States is now the number one wind power producer in the world with over 25,000 MW installed by the end of 2008, according to the Global Wind Energy Council in January 2009.
On a highway, a compact pick-up truck struggles to tow a 30-foot boat up a steep grade. Inside the pick-up, the owner curses himself. He saved money leasing a smaller truck but sees now that he really needed a bigger, pricier vehicle, one suitable for this job.
Today’s ever-evolving global economic engine is, in many ways, a wonderful phenomenon; you know—a rising-tide-lifting-all-boats, trickle-down-theory-of-economics dynamic at work.
Faithful Gear Technology readers may recall that our July 2009 issue contained an update of the deliberations provided by Bill Bradley. Now, almost two years later, there is an ISO/IEC wind turbine gearbox standard out for draft international standard ballot (ballot closes 2011-05-17).
For a high-speed gearbox, an important part of power losses is due to the mesh. A global estimation is not possible and an analytical approach is necessary with evaluations of three different origins of power losses: friction in mesh contact, gear windage and pumping effect between teeth.
We talked energy efficiency with some major players in the lubricants industry— but with a focus on their products’ impact regarding energy efficiency of gears and gearboxes in wind turbines.
This article shows the newest developments to reduce overall cycle time in grinding wind power gears, including the use of both profile grinding and threaded wheel grinding.
Excess lubricant supply in gearing contributes to power loss due to churning as well as the requirements of the lubrication system itself. Normally, a much larger amount of oil than required is used for cooling because so much of it is thrown away by centrifugal force. To lower the amount of lubricant required and reduce those losses, it is necessary to discover the ideal location of the supplying nozzle.
A series of bench-top experiments was conducted to determine the effects of metallic debris being dragged through meshing gear teeth. A test rig that is typically used to conduct contact fatigue experiments was used for these tests. Several sizes of drill material, shim stock and pieces of gear teeth were introduced and then driven through the meshing region. The level of torque required to drive the “chip” through the gear mesh was measured. From the data gathered, chip size sufficient to jam the mechanism can be determined.
This paper describes the research and development of the first production gearbox with asymmetric tooth profiles for the TV7-117S turboprop engine. The paper also presents numerical design data related to development of this gearbox.
Big gears and wind turbines go together like bees and honey, peas and carrots, bread and butter and—well, you get the idea. Wind isn’t just big right now, it’s huge. The wind industry means tremendous things for the energy dependent world we live in and especially big things for gear manufacturers and other beleaguered American industries.
In the field of large power transmission gear units for heavy machine industry, the following two development trends have been highly influential: use of case hardened gears and a branching of the power flow through two or more ways.
The global wind energy market has seen average growth rates of 28 percent over the last 10 years, according to the Global Wind Energy Council (GWEC), creating major challenges for the component supply industry. GWEC also forecasts an average growth rate of 22 percent for the next five years, which if realized, will continue to put pressure on suppliers of turbine components.
In the August 2008 issue of Gear Technology, we ran a story (“Gearbox Speed Reducer Helps Fan Technology for ‘Greener” Jet Fuel Efficiency’) on the then ongoing, extremely challenging and protracted development of Pratt & Whitney’s geared turbofan (GTF) jet engine.
There's a reason they call it catastrophic gear failure: For example, if the line goes down at a large aluminum rolling mill because a gear set goes bad, the cost can run up to a whopping $200,000 a week. Even in smaller operations, the numbers alone (not to mention all the other problems) can be a plant manager's worst nightmare.
Gear flank breakage can be observed on edge zone-hardened gears. It occurs, for example, on bevel gears for water turbines, on spur gears for wind energy converters and on single- and double-helical gears for other industrial applications.
A major source of helicopter cabin noise (which has been measured at over 100 decibels sound pressure level) is the gearbox. Reduction of this noise is a NASA and U.S. Army goal. A requirement for the Army/NASA Advanced Rotorcraft Transmission project was a 10 dB noise reduction compared to current designs.
The major focus of the American Gear Manufacturers Association standards activity has been the accurate determination of a gearbox's ability to transmit a specified amount of power for a given amount of time. The need for a "level playing field" in the critical arena was one of the reasons the association was formed in the first place. Over the past 85 years, AGMA committees have spent countless hours "discussing" the best ways to calculate the rating of a gear set, often arguing vigorously over factors that varied the resulting answers by fractions of a percentage point. While all that "science" was being debated in test labs and conference rooms all over the country, out industry's customers were conducting their own experiments through the daily operation of gear-driven equipment of all types.
LMS International helped a Fiat subsidiary develop a new, dynamic vibro-acoustic prediction method to reduce design time and engineering costs through accurate prediction of gear noise in the design phase.
This paper reviews the necessity for detailed specification, design and manufacture to achieve required performance in service. The precise definition of duty rating and a thorough understanding of the environmental conditions, whether it is in a marine or industrial application, is required to predict reliable performance of a gearbox through its service life. A case study relating to complex marine gears and other general practice is presented to review the techniques used by Allen Gears to design and develop a gearbox that integrates with the requirements of the whole machinery installation. Allen Gears has considerable experience in the design of a variety of industrial and marine gears(Ref. 1,2).
Large marine gearboxes. More than a year in production, each weighing 125,000 pounds, the gearboxes were for U.S. Navy amphibious ships, for combining the power of 10,000 hp diesel engines to drive propeller shafts. They were also the last major gear products shipped from Philadelphia Gear Corp.’s King of Prussia factory.
Today gear drive operations have several options when selecting the proper lubricant for their gearboxes. As in the past, the primary lubricant used for gearbox lubrication is mineral oil. But with the advances in technology, synthetic hydrocarbons (PAOs) and polyglycols show very specific advantages in certain applications. With gear drives becoming more and more precise, it is now also to the benefit of the gear operator to verify that he or she has the proper additive package and viscosity in the lubricant selected. Fig. 1 shoes that a gear oil is a combination of a base oil and specific additives. The base oils can be either mineral oil, a synthetic or even in some cases a combination of the two.
A computational fluid dynamics (CFD) method is adapted, validated and applied to spinning gear systems with emphasis on predicting windage losses. Several spur gears and a disc are studied. The CFD simulations return good agreement with measured windage power loss.
Gear tooth wear and micropitting are very difficult phenomena to predict analytically. The failure mode of micropitting is closely correlated to the lambda ratio. Micropitting can be the limiting design parameter for long-term durability. Also, the failure mode of micropitting can progress to wear or macropitting, and then go on to manifest more severe failure modes, such as bending. The results of a gearbox test and manufacturing process development program will be presented to evaluate super-finishing and its impact on micropitting.
The need for improved power transmissions that use gears and gearboxes with smaller overall dimensions and with lower noise generation has left manufacturing engineers searching for different methods of gear processing. This search has led to the requirement of hardened gears.
The research presented here is part of an ongoing (six years to date) project of the Cluster of Excellence (CoE). CoE is a faculty-wide group of researchers from RWTH Aachen University in Aachen (North Rhine-Westphalia). This presentation is a result of the group’s examination of "integrative production technology for high-wage countries," in which a shaft for a dual-clutch gearbox is developed.
It is widely recognized that the reduction of CO2 requires consistent light-weight design of the entire vehicle. Likewise, the trend towards electric cars requires light-weight design to compensate for the additional weight of battery systems. The need for weight reduction is also present regarding vehicle transmissions. Besides the design of the gearbox housing, rotating masses such as gear wheels and shafts have a significant impact on fuel consumption. The current technology shows little potential of gear weight reduction due to the trade-off between mass optimization and the manufacturing process. Gears are usually forged followed or not by teeth cutting operation.
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Much of the existing guidelines for making large, high-performance gears for wind turbine gearboxes exhibit a need for improvement. Consider: the large grinding stock used to compensate for heat treatment distortion can significantly reduce manufacturing productivity; and, materials and manufacturing processes are two other promising avenues to improvement. The work presented here investigates quenchable alloy steels that, combined with specifically developed Case-hardening and heat treatment processes, exhibits reduced distortion and, in turn, requires a smaller grinding stock.
Light-weight construction and consideration of available resources result in gearbox designs with high load capacity and power density. At the same time, expectations for gear reliability are high. Additionally, there is a diversity of planetary gears for different applications.
The goal of gear drive design is to transit power and motion with constant angular velocity. Current trends in gear drive design require greater load carrying capacity and increased service life in smaller, quieter, more efficient gearboxes. Generally, these goals are met by specifying more accurate gears. This, combined with the availability of user-friendly CNC gear grinding equipment, has increased the use of ground gears.
This article offers an overview of the practical design of a naval gear for combined diesel or gas turbine propulsion (CODOG type). The vibration performance of the gear is tested in a back-to-back test. The gear presented is a low noise design for the Royal Dutch Navy's LCF Frigate. The design aspects for low noise operation were incorporated into the overall gear system design. Therefore, special attention was paid to all the parameters that could influence the noise and vibration performance of the gearbox. These design aspects, such as tooth corrections, tooth loading, gear layout, balance, lubrication and resilient mounting, will be discussed.
Modern gearboxes are characterized by high torque load demands, low running noise and compact design. In order to fulfill these demands, profile and lead modifications are being applied more often than in the past. This paper will focus on how to produce profile and lead modifications by using the two most common grinding processes—threaded wheel and profile grinding. In addition, more difficult modifications—such as defined flank twist or topological flank corrections—will also be described in this paper.
A gearbox that absorbs 30 percent of external forces, transmits power from two engines operating at different speeds, and uses gears that meet several design and specification standards at the same time...
It seems that nothing can hold back the power of the wind—unless, of course, it's the availability of rugged, reliable, specially designed gearboxes. How Gleason is Keeping up with Demand.
Gear manufacturers are moving into an era that will see changes in both engineering practices and industry standards as new end-products evolve. Within the traditional automotive industry, carbon emission reduction legislation will drive the need for higher levels of efficiency and growth in electric and hybrid vehicles. Meanwhile, the fast growing market of wind turbines is already opening up a whole new area of potential for gearbox manufacturers, but this industry is one that will demand reliability, high levels of engineering excellence and precision manufacturing.
I am currently writing a design procedure for the correct method for setting up bevel gears in a gearbox for optimum performance...
The diagnosis and prevention of gear tooth and bearing wear requires the discovery and understanding of the particular mechanism of wear, which in turn indicates the best method of prevention. Because a gearbox is a tribologically dependent mechanism, some understanding of gear and bearing tribology is essential for this process. Tribology is the general term for the study and practice of lubrication, friction and wear. If tribology is neglected or considered insignificant, poor reliability and short life will result.
When Belgium-based Hansen Transmissions was under the ownership of Invensys plc in the late 1990s, the parent company was dropping not-so-subtle hints that the industrial gearbox manufacturer was not part of its long-term plans. Yet Hansen’s CEO Ivan Brems never dreamed that, less than a decade later, he would be working for an Indian company.
This article summarizes the use of laboratory fatigue data for bearings and gears coupled with probabilistic life prediction and EHD theories to predict the life and reliability of a commercial turboprop gearbox.
News Items About gearbox
1 SKFs New Cylindrical Roller Bearings Extend Wind Turbine Gearbox Life (April 11, 2006)
New SKF high-capacity cylindrical roller bearings for wind turbine gearboxes have been engineered to promote longer gearbox service life... Read News
2 Hansen Delivers First Gearbox from Chinese Facility (April 13, 2009)
Hansen Transmissions announced the delivery of the first gearbox manufactured in the new facility in the Beichen Hi-tech Industrial Park,... Read News
3 Excel Gear Designs, Prototypes Navy Gun System Gearboxes (September 10, 2009)
Roscoe, IL-based Excel Gear has transitioned from prototype to production of 38:1 ratio gearboxes designed for positioning the gun mount ... Read News
4 GE Energy Partners with Chinese Co. To Develop Wind Turbine Gearboxes (April 22, 2006)
GE Energy and Nanjing High Speed & Accurate Gear Company (NGC) have agreed to jointly develop gearboxes for GE's 1.5-megawatt wind tu... Read News
5 Romax Releases Gearbox Design Package (October 26, 2012)
Romax Technology, a gearbox, bearing and driveline engineering specialist, has launched a new design software package that will increase ... Read News
6 Renold Introduces Interchangeable Range of Gearboxes and Couplings (May 24, 2007)
Renold will exhibit its SMXtra interchangeable range of gearboxes and fluid couplings, for quarrying applications, at the Hillhead Exhibi... Read News
7 Neeter Drive Gearboxes Transmit Power up to 6600 N-m (April 12, 2006)
The PowerGear range of bevel gearboxes from Neeter Drives is available in sizes 360 and 450 with an extended transmission range of 3,750 ... Read News
8 Rotork Acquires Italian Valve Gearbox Manufacturer (March 9, 2006)
Rotork Controls Ltd. acquired the business and assets of Omag Snc, a gearbox manufacturer based in Milan, Italy. According to Rotork... Read News
9 Ondrives Manufactures Showcase Gearboxes (April 17, 2006)
Ondrives Ltd. of Chesterfield, U.K., manufactured two gearboxes for a pharmaceutical companys teaching purposes. According to th... Read News
10 New Compact Gearbox from ZF Industrial (April 16, 2004)
The CG gearboxes from ZF Industrial are best suited for use in robotic or other automation applications like electronics or other OEM man... Read News
11 Romax Introduces Gearbox Concept Analysis (November 9, 2011)
Romax Technology recently announced the availability of release R14.0 of the precision bearing, gearbox and driveline simulation and anal... Read News
12 New Gearbox from Brevini (December 6, 2003)
The S Series gearbox from Brevini features an epicyclical design that increases the available power from the unit without affecting the o... Read News
13 ZF Opens First U.S. Plant for Wind Turbine Gearboxes (October 4, 2011)
ZF Friedrichshafen AG has opened a plant for the production of wind turbine gearboxes in Gainesville near Atlanta, Georgia. As of 2012, t... Read News
14 KISSsoft Offers Gearbox Variant Calculations (September 1, 2011)
With KISSsys, gearbox variants can now be calculated very efficiently (module KS1). In contrast to the GPK-models, where within the fixed... Read News
15 Excel Gear Launches Gear/Gearbox Optimization Software (October 21, 2010)
Excel-Lent gear/gearbox design and analysis software has been developed by Excel Gear, Inc. and written in Visual Basic.Net. This softwar... Read News
16 Romax Awarded GL Gearbox Design Assessment (August 17, 2011)
Romax Technology has been awarded the GL Renewables (GL) A-Design Assessment for its new range of WT2000 licensed 2 MW gearboxes. Achievi... Read News
17 Ondrives New Gearbox Emphasizes Torque and Speed (April 11, 2006)
A new line of DC motorized worm and wheel reduction gearboxes from Ondrives is fitted with 24V DC motors that operate at 12V DC. Accor... Read News
18 Cotta Transmission Introduces New Creep Drive Gearbox (April 8, 2005)
Cotta's new creep drive transmission is designed to insert in the vehicle driveline after the main transmission. In the creep mode, t... Read News
19 First 7-Speed Gearbox has a Shift Plate of DuPont Zytel (March 26, 2005)
A shift plate made of DuPont Zytel nylon carries the fully integrated gear change control system of DaimlerChryslers 7G-Tronic seve... Read News
20 New Industrial Gear Oil Enhances Gearbox Durability (January 15, 2006)
The new Mobilgear 600 XP Series of premium industrial gear oils was introdu... Read News
21 Vectron’s Viscosity Sensor Detects Oil Change in Gearbox (May 29, 2007)
The low shear ViSmart™ viscosity sensor from Vectron International was recently used to collect real-time viscosity data in an oil-aging ... Read News
22 Lubricant Assists Gearbox Operation (May 28, 2010)
A more efficient wind turbine that will generate even more wind driven electricity is now possible with the introduction of the new Dow U... Read News
23 Gearbox Express to Open Doors Early 2012 (November 7, 2011)
Three power transmission and wind energy veterans have banded together to create Gearbox Express, an independent business focusing on the... Read News
24 David Brown Bharat Forge Opens First Gearbox Center (October 5, 2012)
David Brown Bharat Forge, the Indian joint venture between leading global gearing expert David Brown and Bharat Forge, a global leader in... Read News
25 Broadwind Energy Plans Expansion of Gearbox Capabilities (March 17, 2010)
Broadwind Energy, Inc. recently announced the expansion of its Precision Repair and Engineering services with enhanced megawatt (MW) gear... Read News
26 Brevini’s Gearbox Operates Quietly for Rubber Sheeting Manufacturer (June 21, 2007)
When Primasil, a U.K.-based independent silicone compounder and manufacturer of non-silicone rubber sheeting, discovered its main drive g... Read News
27 New Gearbox for Power Transmission Applications (April 24, 2006)
SIPCO Mechanical Linkage Solution launched its newest addition to the Technogear? product line. The new LC precision planetary series... Read News
28 Hansen Transmissions Establishes Gearbox Facility in India (February 12, 2007)
Hansen Transmissions International announced plans to invest 170 million euros for a wind turbine production plant. The facility will sup... Read News
29 Bonfiglioli Updates Parallel Shaft Series and Bevel-Helical Series Gearboxes (May 31, 2007)
Bonfiglioli recently presented five new sizes in the HDP parallel-shaft series and HDO bevel helical series that was first introduced in ... Read News
30 ArvinMeritor Focuses on Automated Manual Gearboxes (April 15, 2006)
ArvinMeritor announced a decision to place greater emphasis on the sales and marketing of the FreedomLine automated manual transmission b... Read News