Case Depth

GEAR TALK WITH CHUCK | 2018-09-25

Reworking Questions

The most important consideration in deciding whether to rework or scrap and re-make a nonconforming part is functionality. Can the part be made to ...

GEAR TALK WITH CHUCK | 2018-06-05

Hardenability 101

Material Grade in Gears

The reason not all gears can be made from the same material grade has to do with hardenability. We have long unde...

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 | 2018-05-03

That X Factor

Our international readers are no doubt chuckling over this silly, American “long addendum” terminology. The “civilized world” has long relied on a ...

GEAR TALK WITH CHUCK | 2017-04-04

What Makes a Good Design?

In my last post I insisted that good design wins in the marketplace. As a student of automotive history, I am compelled to admit that some very gre...

TECHNICAL ARTICLES | 2016-03-01

Practical Approach to Determining Effective Case Depth of Gas Carburizing

Effective case depth is an important factor and goal in gas carburizing, involving complicated procedures in the furnace and requiring precise control of many thermal parameters. Based upon diffusion theory and years of carburizing experience, this paper calculates the effective case depth governed by carburizing temperature, time, carbon content of steel, and carbon potential of atmosphere. In light of this analysis, carburizing factors at various temperatures and carbon potentials for steels with different carbon content were calculated to determine the necessary carburizing cycle time. This methodology provides simple (without computer simulation) and practical guidance of optimized gas carburizing and has been applied to plant production. It shows that measured, effective case depth of gear parts covering most of the industrial application range (0.020 inch to over 0.250 inch) was in good agreement with the calculation.

FEATURE ARTICLES | 2007-06-01

Wind Turbine Market Leads Hansen Transmissions to India

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.

TECHNICAL ARTICLES | 2005-07-01

Systematic Investigations on the Influence of Case Depth on the Pitting and Bending Strength of Case Carburized Gears

The gear designer needs to know how to determine an appropriate case depth for a gear application in order to guarantee the required load capacity.

INDUSTRY NEWS | 2002-05-01

Industry News

Complete Industry News for May/June 2002.

FEATURE ARTICLES | 1999-11-01

Coordinate Measuring Machines and the Gear Industry

Gears are extremely complex shapes. Coordinate measuring machines, or CMMs, are designed to measure complex shapes. It seems to follow that CMMs world, therefore, be the ideal tool for measuring gears. But the answer is not so simple.

REVOLUTIONS | 1999-07-01

Revolutions

Welcome to Revolutions, the column that brings you the latest, most up-to-date and easy-to-read information about the people and technology of the gear industry.

FEATURE ARTICLES | 1999-03-01

Metallurgical Aspects to be Considered in Gear and Shaft Design

In his Handbook of Gear Design (Ref.1), Dudley states (or understates): "The best gear people around the world are now coming to realize that metallurgical quality is just as important as geometric quality." Geometric accuracy without metallurgical integrity in any highly stressed gear or shaft would only result in wasted effort for all concerned - the gear designer, the manufacturer, and the customer - as the component's life cycle would be prematurely cut short. A carburized automotive gear or shaft with the wrong surface hardness, case depth or core hardness may not even complete its basic warranty period before failing totally at considerable expense and loss of prestige for the producer and the customer. The unexpected early failure of a large industrial gear or shaft in a coal mine or mill could result in lost production and income while the machine is down since replacement components may not be readily available. Fortunately, this scenario is not common. Most reputable gear and shaft manufacturers around the world would never neglect the metallurgical quality of their products.

INDUSTRY NEWS | 1993-07-01

Gear Tip Chamfer and Gear Noise; Surface Measurement of Spiral Bevel Gear Teeth

Could the tip chamfer that manufacturing people usually use on the tips of gear teeth be the cause of vibration in the gear set? The set in question is spur, of 2.25 DP, with 20 degrees pressure angle. The pinion has 14 teeth and the mating gear, 63 teeth. The pinion turns at 535 rpm maximum. Could a chamfer a little over 1/64" cause a vibration problem?

TECHNICAL ARTICLES | 1992-07-01

Comparing Surface Failure Modes in Bearings and Gears: Appearances vs. Mechanisms

In the 1960's and early 1970's, considerable work was done to identify the various modes of damage that ended the lives of rolling element bearings. A simple summary of all the damage modes that could lead to failure is given in Table 1. In bearing applications that have insufficient or improper lubricant, or have contaminants (water, solid particles) or poor sealing, failure, such as excessive wear or vibration or corrosion, may occur, rather than contact fatigue. Usually other components in the overall system besides bearings also suffer. Over the years, builders of transmissions, axles, and gear boxes that comprise such systems have understood the need to improve the operating environment within such units, so that some system life improvements have taken place.

TECHNICAL ARTICLES | 1986-11-01

Curvic Coupling Design

Curvic Couplings were first introduced in 1942 to meet the need for permanent couplings and releasing couplings (clutches), requiring extreme accuracy and maximum load carrying capacity, together with a fast rate of production. The development of the Curvic Coupling stems directly from the manufacture of Zerol and spiral bevel gears since it is made on basically similar machines and also uses similar production methods. The Curvic Coupling can therefore lay claim to the same production advantages and high precision associated with bevel gears.

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.

TECHNICAL ARTICLES | 1984-10-01

Endurance Limit for Contact Stress in Gears

With the publishing of various ISO draft standards relating to gear rating procedures, there has been much discussion in technical papers concerning the various load modification factors. One of the most basic of parameters affecting the rating of gears, namely the endurance limit for either contact or bending stress, has not, however, attracted a great deal of attention.