As the challenges in bevel and hypoid gear manufacturing need to be addressed, the objective of this paper is to show the tool and process design can be optimized based on the results of the manufacturing simulation BevelCut.
The first planetary drive I helped take apart had three stages of through hardened spur gears encased in a simple cast iron tube with plates on both ends. Both input and output shafts rotated on taper roller bearings, but everything else had simple bronze bushings.
For anyone involved in gear manufacturing, Gear Expo is an absolute treasure. In 2013, it was bigger and more varied than it's been in a decade. With 226 exhibitors covering every conceivable gear-related technology, Gear Expo offered visitors unparalleled opportunities to interview potential
new suppliers.
For two days in Saline, Michigan,
Liebherr's clients, customers and
friends came together to discuss the latest gear products and technology. Peter Wiedemann, president of Liebherr Gear Technology Inc., along with Dr.-Ing. Alois Mundt, managing director, Dr.-Ing. Oliver Winkel, head of application technology, and Dr.-Ing. Andreas Mehr, technology development shaping and grinding, hosted a variety of informative presentations.
What's new on the Gear Technology website this month? Videos from DMG Mori-Seiki, the latest e-mail newsletter and updates on upcoming events, including the Kapp-Niles Rocky Mountain Gear School.
This paper introduces mandatory improvements in design, manufacturing and inspection - from material elaboration to final machining - with special focus on today's large and powerful gearing.
The first edition of the international calculation method for micropitting—ISO TR 15144–1:2010—was just published
last December. It is the first and only official, international calculation method established for dealing with
micropitting. Years ago, AGMA published a method for the calculation of oil film thickness containing some comments
about micropitting, and the German FVA published a calculation method based on intensive research results. The FVA and the AGMA methods are close to the ISO TR, but the calculation of micropitting safety factors is new.
Bringing new or improved products to
market sooner has long been proven profitable for companies. One way to help shorten the time-to-market is to accelerate validation testing. That is, shorten the test time required to validate a new or improved product.
When parts you manufacture pass through numerous processes such as deep hole drilling, machining, hobbing and grinding, a CMM is essential when your customers require 100 percent in-process and final inspection.
This article is part four of an eight-part series on the tribology aspects of angular gear drives. Each article will be presented first and exclusively by Gear Technology, but the entire series will be included in Dr. Stadtfeld’s upcoming book on the subject, which is scheduled for release in 2011.
Profile corrections on gears are a commonly used method to reduce transmission error, contact shock, and scoring risk. There are different types of profile corrections. It is a known fact that the type of profile correction used will have a strong influence on the resulting transmission error. The degree of this influence may be determined by calculating tooth loading during mesh. The current method for this calculation is very complicated and time consuming; however,
a new approach has been developed that could reduce the calculation time.
We've contacted many of the gear industry's leading suppliers to find out what they'll be showing at Gear Expo 99. Booth numbers are current as of July 31, 1999, but they are subject to change. A current list of exhibitors and booth information is available at the AGMA Web site at www.agma.org.
Today's high technology hobs are visible different from their predecessors. Gear hobs have taken on a different appearance and function with present day technology and tool and material development. This article shows the newer products being offered today and the reasons for investigating their potential for use in today's modern gear hobbers, where cost reduction and higher productivity are wanted.
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.
A universal gear is one generated by a common rack on a cylindrical, conical, or planar surface, and whose teeth can be oriented parallel or skewed, centered, or offset, with respect to its axes. Mating gear axes can be parallel or crossed, non-intersecting or intersecting, skewed or parallel, and can have any angular orientation (See Fig.1) The taper gear is a universal gear. It provides unique geometric properties and a range of applications unmatched by any other motion transmission element. (See Fig.2) The taper gear can be produced by any rack-type tool generator or hobbing machine which has a means of tilting the cutter or work axis and/or coordinating simultaneous traverse and infeed motions.
Six years ago this month, the very first issue of Gear Technology, the Journal of Gear Manufacturing, went to press. The reason for starting the publication was a straightforward one: to provide a forum for the presentation of the best technical articles on gear-related subjects from around the world. We wanted to give our readers the information they need to solve specific problems, understanding new technologies, and to be informed about the latest applications in gear design and manufacturing. The premise behind Gear Technology was also a straightforward one: the better informed our readers were about the technology, the more competitive they and their companies would be int he world gear market.
Involute spur gears are very sensitive to gear misalignment. Misalignment will cause the shift of the bearing contact toward the edge of the gear tooth surfaces and transmission errors that increase gear noise. Many efforts have been made to improve the bearing contact of misaligned spur gears by crowning the pinion tooth surface. Wildhaber(1) had proposed various methods of crowning that can be achieved in the process of gear generation. Maag engineers have used crowning for making longitudinal corrections (Fig. 1a); modifying involute tooth profile uniformly across the face width (Fig. 1b); combining these two functions in Fig. 1c and performing topological modification (Fig. 1d) that can provide any deviation of the crowned tooth surface from a regular involute surface. (2)
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.
The use of plastic gearing is increasing steadily in new products.
This is due in part to the availability of recent design data. Fatigue
stress of plastic gears as a function of diametral pitch, pressure angle,
pitch line velocity, lubrication and life cycles are described based
on test information. Design procedures for plastic gears are presented.
What was once recognized as the unique
genius of America is now slipping away
from us and, in many areas, is now seen as a "second rate" capability. Unless
action is taken now, this country
is in real danger of being unable to regain its supremacy in technological development and economic vigor. First Americans must understand the serious implications of the problem; and second, we must dedicate ourselves to national and local actions that will ensure a greater scientific and
technological literacy in America.
