automotive transmissions - Search Results

Articles About automotive transmissions


Articles are sorted by RELEVANCE. Sort by Date.

1 The Guy Who Put the Gearbox Up Front (May 2017)

As the Indianapolis 500 begins its second hundred years, it is a good opportunity to recall the guy who put the gearbox "up front."

2 CTI Symposium USA 2019 (May 2019)

The Past, Present and Future of Vehicle Electrification

3 The Electric Evolution (June 2019)

CTI Symposium Presents Latest Automotive Transmission Developments and Applications.

4 Gear Noise Prediction in Automotive Transmissions (August 2015)

Due to increasing requirements regarding the vibrational behavior of automotive transmissions, it is necessary to develop reliable methods for noise evaluation and design optimization. Continuous research led to the development of an elaborate method for gear noise evaluation. The presented methodology enables the gear engineer to optimize the microgeometry with respect to robust manufacturing.

5 Bending Fatigue, Impact and Pitting Resistance of Ausform-Finished PM Gears (June 2010)

The powder metal (P/M) process is making inroads in automotive transmission applications due to substantially lower costs of P/M-steel components for high-volume production, as compared to wrought or forged steel parts. Although P/M gears are increasingly used in powered hand tools, gear pumps and as accessory components in automotive transmissions, P/M-steel gears are currently in limited use in vehicle transmission applications. The primary objective of this project was to develop high-strength P/M-steel gears with bending fatigue, impact resistance and pitting fatigue performance equivalent to current wrought steel gears.

6 Transmission Throwdown (May 2017)

Which transmission system will come out on top is a hot topic in the automotive community. With multiple transmission-centric conferences on the horizon, there will be plenty of debate, but how much will the answer actually affect gear manufacturers, and when?

7 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.

8 Gear Backlash Analysis of Unloaded Gear Pairs in Transmissions (June 2016)

A best practice in gear design is to limit the amount of backlash to a minimum value needed to accommodate manufacturing tolerances, misalignments, and deflections, in order to prevent the non-driving side of the teeth to make contact and rattle. Industry standards, such as ANSI/AGMA 2002 and DIN3967, provide reference values of minimum backlash to be used in the gear design. However, increased customers' expectations in vehicle noise eduction have pushed backlash and allowable manufacturing tolerances to even lower limits. This is especially true in the truck market, where engines are quieter because they run at lower speeds to improve fuel economy, but they quite often run at high torsional vibration levels. Furthermore, gear and shaft arrangements in truck transmissions have become more complex due to increased number of speeds and to improve efficiency. Determining the minimum amount of backlash is quite a challenge. This paper presents an investigation of minimum backlash values of helical gear teeth applied to a light-duty pickup truck transmission. An analytical model was developed to calculate backlash limits of each gear pair when not transmitting load, and thus susceptible to generate rattle noise, through different transmission power paths. A statistical approach (Monte Carlo) was used since a significant number of factors affect backlash, such as tooth thickness variation; center distance variation; lead; runout and pitch variations; bearing clearances; spline clearances; and shaft deflections and misalignments. Analytical results identified the critical gear pair, and power path, which was confirmed experimentally on a transmission. The approach presented in this paper can be useful to design gear pairs with a minimum amount of backlash, to prevent double flank contact and to help reduce rattle noise to lowest levels.

9 Design and Optimization of a Hybrid Vehicle Transmission (May 2019)

The paper is not the proof of a discovery, but it is the description of a method: the optimization of the microgeometry for cylindrical gears. The method has been applied and described on some transmissions with helical gears and compound epicyclic, used on different hybrid vehicles. However, the method is also valid for industrial gearboxes.

10 The Capacity of Superfinished Vehicle Components to Increase Fuel Economy, Part I (January/February 2009)

This paper will present data from both laboratory and field testing demonstrating that superfinished components exhibit lower friction, operating temperature, wear and/ or higher horsepower, all of which translate directly into increased fuel economy.

11 Oil-Off Characterization Method Using In-Situ Friction Measurement for Gears Operating Under Loss-of-Lubrication Conditions (June 2019)

The oil-off (also known as loss-of-lubrication or oil-out) performance evaluation of gears is of significant interest to the Department of Defense and various rotorcraft manufacturers, so that the aircraft can safely land in an accidental loss-of-lubricant situation. However, unlike typical gear failure modes such as pitting or bending fatigue where early detection is possible, gear failure in an oil-off situation is very rapid and likely catastrophic. Failures rapidly result in the loss of torque transmission and the inability to control the aircraft.

12 Setting a Hundred-Year Standard (June 2018)

Remembering Panhard and Levassor, the company that invented the first manual transmission.

13 Predicted Scuffing Risk to Spur and Helical Gears in Commercial Vehicle Transmissions (November/December 2012)

AGMA925–A03 scuffing risk predictions for a series of spur and helical gear sets of transmissions used in commercial vehicles ranging from SAE Class 3 through Class 8.

14 Dynamic Loads in Parallel Shaft Transmissions - Part 2 (May/June 1990)

Solutions to the governing equations of a spur gear transmission model, developed in a previous article are presented. Factors affecting the dynamic load are identified. It is found that the dynamic load increases with operating speed up to a system natural frequency. At operating speeds beyond the natural frequency the dynamic load decreases dramatically. Also, it is found that the transmitted load and shaft inertia have little effect upon the total dynamic load. Damping and friction decrease the dynamic load. Finally, tooth stiffness has a significant effect upon dynamic loadings the higher the stiffness, the lower the dynamic loading. Also, the higher the stiffness, the higher the rotating speed required for peak dynamic response.

15 Dynamic Loads in Parallel Shaft Transmissions Part 1 (March/April 1990)

Recently, there has been increased interest in the dynamic effects in gear systems. This interest is stimulated by demands for stronger, higher speed, improved performance, and longer-lived systems. This in turn had stimulated numerous research efforts directed toward understanding gear dynamic phenomena. However, many aspects of gear dynamics are still not satisfactorily understood.

16 Development of Conical Involute Gears (Beveloids) for Vehicle Transmissions (November/December 2005)

Conical involute gears (beveloids) are used in transmissions with intersecting or skewed axes and for backlash-free transmissions with parallel axes.

17 Trends in Automobile Transmissions (July/August 2006)

With all the work in transmission development these days, the demand for automobile transmission gears should remain strong for several years, but suppliers will have to be as flexible as possible to keep up with the changes.

18 New Transmissions Drive Automotive Gear Industry (July/August 2006)

News from the major automakers and transmission suppliers.

19 Optimism in Wind Abounds (January/February 2009)

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.

20 Grinding Gears for Racing Transmissions (September/October 2009)

When you push 850 horsepower and 9,000 rpm through a racing transmission, you better hope it stands up. Transmission cases and gears strewn all over the racetrack do nothing to enhance your standing, nor that of your transmission supplier.

21 Wind Turbine Market Leads Hansen Transmissions to India (June 2007)

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.

22 Gearheads Rejoice! The Internal Combustion Engine is Back (May 2011)

The opposed-piston internal combustion engine is making a comeback.

23 Electric Vehicle Whine Noise - Gear Blank Tuning as an Optimization Option (March/April 2019)

Noise issues from gear and motor excitation whine are commonly faced by many within the EV and HEV industry. In this paper the authors present an advanced CAE methodology for troubleshooting and optimizing such NVH phenomenon.

24 Low-Distortion Heat Treatment of Transmission Components (October 2011)

This paper presents how low pressure carburizing and high pressure gas quenching processes are successfully applied on internal ring gears for a six-speed automatic transmission. The specific challenge in the heat treat process was to reduce distortion in such a way that subsequent machining operations are entirely eliminated.

25 The Road to Reliability (May 2018)

Gear Industry Steps Up to Automation Challenges in Auto Industry. Automotive parts are always moving. They are zipping across conveyors, smashing into each other in bins and traveling across the production chain before ending up inside an automobile. For gears, this can be a somewhat precarious situation as they tend to run best when they're free from nicks, abrasions, cracks or other damages.

26 Hypoloid Gear with Small Shaft Angles and Zero-to-Large Offsets (November/December 2009)

Beveloid gears are used to accommodate a small shaft angle. The manufacturing technology used for beveloid gearing is a special setup of cylindrical gear cutting and grinding machines. A new development, the so-called Hypoloid gearing, addresses the desire of gear manufacturers for more freedoms. Hypoloid gear sets can realize shaft angles between zero and 20° and at the same time, allow a second shaft angle (or an offset) in space that provides the freedom to connect two points in space.

27 Updating Modern Production Processes (August 2016)

Gear Technology interviews Scott Yoders of Liebherr about the latest gear machining technologies of relevance to automotive manufacturers.

28 Noise Reduction in an EV Hub Drive Using a Full Test and Simulation Methodology (May 2016)

With the ongoing push towards electric vehicles (EVs), there is likely to be increasing focus on the noise impact of the gearing required for the transmission of power from the (high-speed) electric motor to the road. Understanding automotive noise, vibration and harshness (NVH) and methodologies for total in-vehicle noise presupposes relatively large, internal combustion (IC) contributions, compared to gear noise. Further, it may be advantageous to run the electric motors at significantly higher rotational speed than conventional automotive IC engines, sending geartrains into yet higher speed ranges. Thus the move to EV or hybrid electric vehicles (HEVs) places greater or different demands on geartrain noise. This work combines both a traditional NVH approach (in-vehicle and rig noise, waterfall plots, Campbell diagrams and Fourier analysis) - with highly detailed transmission error measurement and simulation of the complete drivetrain - to fully understand noise sources within an EV hub drive. A detailed methodology is presented, combining both a full series of tests and advanced simulation to troubleshoot and optimize an EV hub drive for noise reduction.

29 New Transmissions Make the Gas GREENER (July 2015)

“Highway vehicles release about 1.7 billion tons of greenhouse gases (GHGs) into the atmosphere each year — mostly in the form of carbon dioxide (CO2) — contributing to global climate change. The CO2 emissions of a car are directly proportional to the quantity of fuel consumed by an engine. In 2013, U.S. greenhouse gas emissions from transportation were second only to the electricity sector — an increase of about 16% since 1990.” (EPA.GOV).

30 Setting Load Parameters for Viable Fatigue Testing of Gears in Powertrain Axles Part I: Single-Reduction Axles (August 2014)

This presentation introduces a new procedure that - derived from exact calculations - aids in determining the parameters of the validation testing of spiral bevel and hypoid gears in single-reduction axles.

31 Automotive Transmission Design Using Full Potential of Powder Metal (August 2013)

For metal replacement with powder metal (PM) of an automotive transmission, PM gear design differs from its wrought counterpart. Indeed, complete reverse-engineering and re-design is required so to better understand and document the performance parameters of solid-steel vs. PM gears. Presented here is a re-design (re-building a 6-speed manual transmission for an Opel Insignia 4-cylinder, turbocharged 2-liter engine delivering 220 hp/320 N-m) showing that substituting a different microgeometry of the PM gear teeth -- coupled with lower Young’s modulus -- theoretically enhances performance when compared to the solid-steel design.

32 Boom or Bust - Are You in the Right Markets (June/July 2013)

Over the past few months we've talked with a lot of gear manufacturers. Many of them tell us business is strong, while others are struggling with reduced demand. The difference between them isn't so much in the quality of their manufacturing operations, but rather trends in the end markets they serve.

33 Talking Truth to Power: Plastic Gears Taking Back Seat to No One (March/April 2013)

Automotive industry embraces proven yet evolving technology of plastic gears.

34 QS - 9000 Rules (November/December 1995)

Ready or not, QS-9000 is here. If you are a first-tier supplier to one of the Big Three automotive companies, you've already heard that compliance with this new quality standard is now an entry-level requirement for doing business with Ford, General Motors and Chrysler. If you're a second-or third-tier supplier, you can expect the ripple effect of this new standard to hit your company one way or another.

35 Investigation of Gear Rattle Phenomena (September/October 1992)

The acceptance by discerning customers of passenger cars is dependent upon both the actual noise lever and the subjective noise character. The subjective noise character itself can contain, among other features, undesirable noise phenomena which become apparent at certain points in the vehicle operating range. One such critical phenomenon is gear rattle, which is mainly present under low speed, high load conditions. Due to changes in the angular velocity of the crankshaft, gear rattle under driving conditions occurs at the unloaded gears and splines.

36 The Effect of Reverse Hobbing at a High Speed (March/April 1987)

Today it is common practice when climb hobbing to keep the direction of the hob thread the same as that of the helical gear. The same generalization holds true for the mass production of gears for automobiles. It is the authors' opinion, however, that conventional hobbing with a reverse-handed hob is more effective for the high-speed manufacture of comparatively small module gears for automobiles. The authors have proven both experimentally and theoretically that reverse-handed conventional hobbing, using a multi-thread hob with a smaller diameter is very effective for lengthening the life of the hob and for increasing cutting efficiency at high speeds.

37 NVH Potential of PM Gears for Electrified Drivetrains (September/October 2018)

Electrification has already started to have a noticeable impact on the global automotive industry. As a result, the drivetrains of hybrid (HEV) and full electric vehicles (EV) are facing many challenges, like increased requirements for NVH in high speed e-Drives and the need for performance improvements to deal with recuperation requirements. Motivated by the positive validation results of surface densified manual transmission gears which are also applicable for dedicated hybrid transmissions (DHTs) like e-DCTs, GKN engineers have been looking for a more challenging application for PM gears within those areas.

38 Hybrid, Alternative Drivetrains Take Center Stage at CTI Symposium (May 2010)

As the automotive industry continues to reinvent itself, new transmission technologies are at the forefront of this effort, and there is a whirlwind of new developments being detailed at the German Car Training Institute’s Automotive Transmissions and Drive Trains Symposium North America.