power loss - Search Results

Articles About power loss

Articles are sorted by RELEVANCE. Sort by Date.

1 Determining Power Losses in the Helical Gear Mesh (September/October 2005)

This article reviews mathematical models for individual components associated with power losses, such as windage, churning, sliding and rolling friction losses.

2 Flank Load Carrying Capacity and Power Loss Reduction by Minimized Lubrication (May 2011)

The objective of this study was to investigate the limits concerning possible reduction of lubricant quantity in gears that could be tolerated without detrimental effects on their load carrying capacity.

3 A Model of the Pumping Action Between the Teeth of High-Speed Spur and Helical Gears (May/June 2004)

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.

4 How to Minimize Power Losses in Transmissions, Axles and Steering Systems (September 2012)

By increasing the number of gears and the transmission-ratio spread, the engine will run with better fuel efficiency and without loss of driving dynamics. Transmission efficiency itself can be improved by: using fuelefficient transmission oil; optimizing the lubrication systems and pumps; improving shifting strategies and optimizing gearings; and optimizing bearings and seals/gaskets.

5 Low Loss Gears (June 2007)

In most transmission systems, one of the main power loss sources is the loaded gear mesh. In this article, the influences of gear geometry parameters on gear efficiency, load capacity, and excitation are shown.

6 Understanding Fluid Flow to Improve Lubrication Efficiency (January/February 2004)

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.

7 CFD Technology for Rotorcraft Gearbox Windage Aerodynamics Simulation (August 2009)

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.

8 Full-Load Testing of Large Gearboxes Using Closed-Loop Power Circulation (September/October 1991)

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.

9 Lubricant Jet Flow Phenomena in Spur and Helical Gears (January/February 1987)

In the gearing industry, gears are lubricated and cooled by various methods. At low to moderate speeds and loads, gears may be partly submerged in the lubricant which provides lubrication and cooling by splash lubrication. With splash lubrication, power loss increases considerably with speed. This is partially because of churning losses. It is shown that gear scoring and surface pitting can occur when the gear teeth are not adequately lubricated and cooled.

10 Development of High-Hardness-Cast Gears for High-Power Mining Applications (January/February 2017)

Multiple possibilities are available to increase the transmissible power of girth gears. These solutions include: using a larger module, increasing of the gear diameter through the number of teeth, enlarging the face width, and increasing the hardness of the base material. The first three parameters are mostly limited by cutting machine capability. Module, outside diameter, and face width (for a cast gear) can theoretically be increased to infinity, but not the cutting machine dimensions. There are also practical limits with respect to the installation of very large diameter/large face width gears.

11 Getting the Right Tools (September/October 2014)

So there is little chance that they need the same software to assist with their work. Gone are the days when companies wrote their own code and process engineers thumbed the same tattered reference book.

12 Thermal Behavior of Helical Gears (May 2007)

An experimental effort has been conducted on an aerospace-quality helical gear train to investigate the thermal behavior of the gear system as many important operational conditions were varied.

13 NOME Is Where The Energy Is (May 2016)

According to the U.K.-based WITT Energy website (witt-energy.com), “The WITT is the only device in the world that can capture energy from all movement and turn it into electricity. No other energy system can exploit the full spectrum of movement, enabling it to harvest power from water (sea, river or tidal), wind and human or animal motion.”

14 An Experimental Investigation of Aerospace-Quality Gears Operating in Loss-of-Lubrication Condition (August 2013)

This work establishes a baseline for aerospace spur gear behavior under oil-off conditions. The collected test results document a different oil-off time, dictated by material used.

15 Power Skiving of Cylindrical Gears on Different Machine Platforms (January/February 2014)

It has long been known that the skiving process for machining internal gears is multiple times faster than shaping, and more flexible than broaching, due to skiving's continuous chip removal capability. However, skiving has always presented a challenge to machines and tools. With the relatively low dynamic stiffness in the gear trains of mechanical machines, as well as the fast wear of uncoated cutters, skiving of cylindrical gears never achieved acceptance in shaping or hobbing, until recently.

16 Oil-Out Endurance Under the Lens (January/February 2017)

Oil-out conditions, or conditions in which an aircraft is operating without any oil in its gearbox or transmission, are devastating for an aircraft's hardware. Even the sturdiest gears usually can’t last 30 minutes under such conditions before they catastrophically fail, and the whole system usually follows shortly after. That doesn’t leave pilots with a whole lot of time to find a suitable location to land in the case of an oil-out emergency.

17 Design Formulas for Evaluating Contact Stress in Generalized Gear Pairs (May/June 2001)

A very important parameter when designing a gear pair is the maximum surface contact stress that exists between two gear teeth in mesh, as it affects surface fatigue (namely, pitting and wear) along with gear mesh losses. A lot of attention has been targeted to the determination of the maximum contact stress between gear teeth in mesh, resulting in many "different" formulas. Moreover, each of those formulas is applicable to a particular class of gears (e.g., hypoid, worm, spiroid, spiral bevel, or cylindrical - spur and helical). More recently, FEM (the finite element method) has been introduced to evaluate the contact stress between gear teeth. Presented below is a single methodology for evaluating the maximum contact stress that exists between gear teeth in mesh. The approach is independent of the gear tooth geometry (involute or cycloid) and valid for any gear type (i.e., hypoid, worm, spiroid, bevel and cylindrical).

18 Optimizing Gear Geometry for Minimum Transmission Error, Mesh Friction Losses and Scuffing Risk Through Computer- Aided Engineering (August 2010)

Minimizing gear losses caused by churning, windage and mesh friction is important if plant operating costs and environmental impact are to be minimized. This paper concentrates on mesh friction losses and associated scuffing risk. It describes the preliminary results from using a validated, 3-D Finite Element Analysis (FEA) and Tooth Contact Analysis (TCA) program to optimize cylindrical gears for low friction losses without compromising transmission error (TE), noise and power density. Some case studies and generic procedures for minimizing losses are presented. Future development and further validation work is discussed.

19 Going to Gear Expo (September 2013)

Like many of you in the gear industry, we’ve been working extremely hard over the past few months getting ready for Gear Expo 2013, which takes place September 17-19 in Indianapolis.

20 Reaching Out (March/April 2011)

Publisher Michael Goldstein describes the success of Gear Technology's new e-mail newsletter programs.

21 Drive Line Analysis for Tooth Contact Optimization of High-Power Spiral Bevel Gears (June/July 2011)

In the majority of spiral bevel gears, spherical crowning is used. The contact pattern is set to the center of the active tooth flank and the extent of the crowning is determined by experience. Feedback from service, as well as from full-torque bench tests of complete gear drives, has shown that this conventional design practice leads to loaded contact patterns, which are rarely optimal in location and extent. Oversized reliefs lead to small contact area, increased stresses and noise, whereas undersized reliefs result in an overly sensitive tooth contact.

22 Gear Applications All the Rage at Windpower 2010 (June 2010)

Capitalizing on a burgeoning new technology where gears are of great import, the gear community gathered en masse at the American Wind Energy Association’s Windpower Expo 2010.

23 High Power Transmission with Case-hardened Gears and Internal Power Branching (January/February 1985)

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.

24 Windpower 2009 Relocates in Light of Record Growth (January/February 2009)

It’s not too often a trade show so far surpasses organizers’ expectations for size that it must be relocated. This was just the dilemma the American Wind Energy Association (AWEA) faced with the Windpower 2009 Conference and Exhibition, which was originally scheduled to take place in Minneapolis, but will now be held at McCormick Place, Chicago.

25 Rattle: Addressing Gear Noise in a Power Take-off (January/February 2012)

At Muncie Power, the objective of noise and vibration testing is to develop effective ways to eliminate power take-off (PTO) gear rattle, with specific emphasis on PTO products. The type of sound of largest concern in this industry is tonal.

26 Single Flank Measuring; Estimating Horsepower Capacity (September/October 1991)

Question: What is functional measurement and what is the best method for getting truthful answers?

27 Experimental Characterization of Bending Fatigue Strength in Gear Teeth (January/February 2003)

The effort described in this paper addresses a desire in the gear industry to increase power densities and reduce costs of geared transmissions. To achieve these objectives, new materials and manufacturing processes, utilized in the fabrication of gears, and being evaluated. In this effort, the first priority is to compare the performance of gears fabricated using current materials and processes. However, once that priority is satisfied, it rapidly transforms to requiring accurate design data to utilize these novel materials and processes. This paper describes the effort to address one aspect of this design data requirement.

28 Light-Weight Design for Planetary Gear Transmissions (September 2013)

There is a great need for future powertrains in automotive and industrial applications to improve upon their efficiency and power density while reducing their dynamic vibration and noise initiation. It is accepted that planetary gear transmissions have several advantages in comparison to conventional transmissions, such as a high power density due to the power division using several planet gears. This paper presents planetary gear transmissions, optimized in terms of efficiency, weight and volume.

29 Load Distribution in Planetary Gears (May/June 2001)

Two-shaft planetary gear drives are power-branching transmissions, which lead the power from input to output shaft on several parallel ways. A part of the power is transferred loss-free as clutch power. That results in high efficiency and high power density. Those advantages can be used optimally only if an even distribution of load on the individual branches of power is ensured. Static over-constraint, manufacturing deviations and the internal dynamics of those transmission gears obstruct the load balance. With the help of complex simulation programs, it is possible today to predict the dynamic behavior of such gears. The results of those investigations consolidate the approximation equations for the calculation of the load factors...

30 What the Internet Means To Your Gear Business (July/August 1998)

Let's face it. The Internet is still, to many of us, exciting, confusing, terrifying and frustrating by turns. The buzzwords change so fast that even the most high tech companies have a hard time keeping up. Cyberspace. Firewall, Java. E-commerce. The list goes on.

31 Internet Adventures, Part II powertransmission.com (January/February 1997)

In July of 1996 we introduced the gear community to the Internet in these pages through the Gear Industry Home Page (GIHP). This electronic buyers guide for gear machine tools, tooling, accessories and services has proven to be more popular than we could have envisioned. In our first month, we had over 3,000 hits, and in our third month, we have over 4,500. By our fourth month, we topped the 7,000 mark, and we are on our way to 11,000 hits in November. As our advertisers develop their own home sites in order to offer layers of information about their companies, their products and services, we expect this activity will increase even more.

32 Industry News (October 2013)

The complete Industry News section from the October 2013 issue of Gear Technology.