TOPICS CALENDAR BUYER'S GUIDE AGMA

Shot Peening

TECHNICAL ARTICLES | 2024-12-12

Experimental and Analytical Study of the Effect of Shot Peening on Gear Micropitting and Contact Fatigue Failure

This study aims to investigate the effect of this identified type of shot peening on the micropitting resistance of the gear tooth flanks and the macropitting resistance and to compare the experimental results with the calculation results based on standard methods.

TECHNICAL ARTICLES | 2022-07-15

IGS to Increase Wind Gearbox Torque Density

To increase cost efficiency in wind turbines, the wind industry has seen a significant rise in power density and an increase in the overall size of geared components. Current designs for multimegawatt turbines demand levelized cost of energy (LCOE) reduction, and the gearbox is a key part of this process. Since fatigue failures nearly always occur at or near the surface, where the stresses are greatest, the surface condition strongly affects the gear life. Consequently, an improved surface condition effectively avoids major redesign or increased material cost due to an increase in part size. Additional finishing methods such as shot peening (SP) and superfinishing (SF) significantly increase the gear load capacity, but these effects have not yet been adequately considered in the current ISO 6336 standard or in any other gear standards. The combination of SP followed by SF will be described here as an “improved gear surface” (IGS).

TECHNICAL ARTICLES | 2022-04-25

Tooth Root Bending Strength of Shot-Peened Gears Made of High-Purity Steels up to the VHCF Range

Standardized methods, like AGMA 2001-D04 or ISO 6336 for the calculation of the load carrying capacities of gears are intentionally conservative to ensure broad applicability in industrial practice. However, new applications and higher requirements often demand more detailed design calculations nowadays; for example: long operating lives in wind power gearboxes or fewer gear stages and higher speeds in e-mobility applications result in higher load cycles per tooth in a gearbox.

TECHNICAL ARTICLES | 2021-03-01

Effects of Different Shot Peening Treatments in Combination with a Superfinishing Process on the Surface Durability of Case-Hardened Gears

How the increasing demands on power transmission and reduction in mass of modern gearboxes lead to gear designs that are close to their load-carrying capacity limits.

GEAR TALK WITH CHUCK | 2019-05-24

Finding the Limits

Jim Richard’s account of his journey from youthful experimenter to designer of cutting edge gear processing equipment illustrates the amazing thing...

TECHNICAL ARTICLES | 2018-09-01

Influence of Different Manufacturing Processes on Properties of Surface-Densified PM Gears

The properties of both shot-peened and cold rolled PM gears are analyzed and compared. To quantify the effect of both manufacturing processes, the tooth root bending fatigue strength will be evaluated and compared to wrought gears.

TECHNICAL ARTICLES | 2018-08-01

Influences of the Residual Stress Condition on the Load-Carrying Capacity of Case-Hardened Gears

Highly loaded gears are usually casehardened to fulfill the high demands on the load-carrying capacity. Several factors, such as material, heat treatment, or macro and micro geometry, can influence the load-carrying capacity. Furthermore, the residual stress condition also significantly influences load-carrying capacity. The residual stress state results from heat treatment and can be further modified by manufacturing processes post heat treatment, e.g. grinding or shot peening.

GEAR TALK WITH CHUCK | 2018-05-31

Parsing the Fine Print

If my last posting prompted you to look at a copy of a material cert, you probably noticed that the cert has much more information on it than just ...

GEAR TALK WITH CHUCK | 2018-05-24

The Right Stuff

Even the most brilliant gear design will fail if the wrong material is used to make the parts. Our understanding of metallurgy and alloying element...

GEAR TALK WITH CHUCK | 2015-05-26

Short Lived Gearbox Designs

“All memorable quotations referring to gearboxes involve expletives.” Peter Wright The author of Fo...

ASK THE EXPERT | 2014-08-01

The Pros and Cons of Fully Ground Root Fillets

For maximum life in carburized and ground gearing, I have been advised that fully grinding a radius into the root gives maximum resistance against fatigue failures. Others have advised that a hobbed and unground radius root form is best. Which is best, and why?

EVENTS | 2011-06-01

Technical Calendar

The complete Technical Calendar from the June/July 2011 issue of Gear Technology.

EVENTS | 2010-03-01

Shot Peening Up Close and Personal

U.S. Shot Peening and Blast Cleaning Workshop.

TECHNICAL ARTICLES | 2005-11-01

Utilization of Powder Metal and Shot Peening Residual Stress to Maximize Cost and Performance Benefit of Highly Loaded Gearing

This article focuses on bending fatigue strength improvements of P/M gearing from recent improvements in P/M technology, combined with shot peening.

TECHNICAL ARTICLES | 1998-01-01

Influence of Gear Design on Gearbox Radiated Noise

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.

PUBLISHER'S PAGE | 1997-03-01

Spreading The Word

Long-time readers of these pages will know that I have always felt strongly about the subject of professional education. There's nothing more important for an individual's career development than keeping up with current technology. likewise, there's nothing more important that a company can do for itself and it employees than seeing to it they have the professional education they need. Giving people the educational tools they need to do their jobs is a necessary ingredient for success.

TECHNICAL ARTICLES | 1992-01-01

Optimum Shot Peening Specification - II

Following is the second part of an article begun in our last issue. The first part covered basic shot peening theory, shot peening controls, and considerations that should go into developing a shot peening specification. Part II covers optional peening methods and the relationship of shot peening specifications to the drawings.

TECHNICAL ARTICLES | 1991-11-01

Optimum Shot Peening Specification - I

Shot peening is widely recognized as a prove, cost-effective process to enhance the fatigue characteristics of metal parts and eliminate the problems of stress corrosion cracking. Additional benefits accrue in the areas of forming and texturizing. Though shot peening is widely used today, the means of specifying process parameters and controlling documents for process control are not widely understood. Questions regarding shot size, intensity, and blueprint specification to assure a high quality and repeatable shot peening process are continually asked by many design and materials engineers. This article should answer many of the questions frequently asked by engineering professionals and to further assist companies interested in establishing a general shot peening specification.

TECHNICAL ARTICLES | 1988-01-01

KHV Planetary Gearing - Part II

Consisting of only a ring gear b meshing with one or two planets a, a carrier H and an equal velocity mechanism V, a KHV gearing(Fig. 1) is compact in structure, small in size and capable of providing a large speed ratio. For a single stage, its speed ratio can reach up to 200, and its size is approximately 1/4 that of a conventional multi-stage gear box.

TECHNICAL ARTICLES | 1986-09-01

Improved Gear Life Through Controlled Shot Peening

The search for greater gear life involves improvement in cost, weight and increased power output. There are many events that affect gear life, and this paper addresses those relating to fatigue, gear tooth pitting, fatigue strength losses due to the heat treating processes and shot peening technique. The capability of shot peening to increase fatigue strength and surface fatigue life eliminate machine marks which cause stress risers, and to aid in lubrication when properly controlled, suggests increased use and acceptance of the process.

FEATURE ARTICLES | 1986-09-01

Tooth Strength Study of Spur Planet Gears

In the design of any new gear drive, the performance of previous similar designs is very carefully considered. In the course of evaluating one such new design, the authors were faced with the task of comparing it with two similar existing systems, both of which were operating quite successfully. A problem arose, however, when it was realized that the bending stress levels of the two baselines differed substantially. In order to investigate these differences and realistically compare them to the proposed new design, a three-dimensional finite-element method (FEM) approach was applied to all three gears.

FEATURE ARTICLES | 1986-09-01

Engineering Constants

Rules and Formula for Gear Sizes

INDUSTRY NEWS | 1986-07-01

Bevel Gear Development and Testing Procedure

The most conclusive test of bevel and hypoid gears is their operation under normal running conditions in their final mountings. Testing not only maintains quality and uniformity during manufacture, but also determines if the gears will be satisfactory for their intended applications.

FEATURE ARTICLES | 1986-05-01

A Wheel Selection Technique for Form Gear Grinding

Until recently, form gear grinding was conducted almost exclusively with dressable, conventional abrasive grinding wheels. In recent years, preformed, plated Cubic Boron Nitride (CBN) wheels have been introduced to this operation and a considerable amount of literature has been published that claim that conventional grinding wheels will be completely replaced in the future. The superior machining properties of the CBN wheel are not disputed in this paper.

TECHNICAL ARTICLES | 1986-05-01

Identification of Gear Noise with Single Flank Composite Measurement

Anyone involved in the design, manufacture and use of gears is concerned with three general characteristics relative to their application: noise, accuracy, and strength or surface durability. In the article, we will be dealing with probably the most aggravating of the group, gear noise.

FEATURE ARTICLES | 1986-01-01

Effect of Shot Peening on Surface Fatigue Life of Carburized and Hardened AISI 1910 Spur Gears

Gear surface fatigue endurance tests were conducted on two groups of 10 gears each of carburized and hardened AlSI 9310 spur gears manufactured from the same heat of material

FEATURE ARTICLES | 1984-05-01

Gear Design

A gear can be defined as a toothed wheel which, when meshed with another toothed wheel with similar configuration, will transmit rotation from one shaft to another. Depending upon the type and accuracy of motion desired, the gears and the profiles of the gear teeth can be of almost any form.