Hollow rolling element bearings

A low mass rolling element with a lightweight core and hollow center was developed for use in bearings. The core is plated so as to provide a hard surface and increase the life and reliability of the high speed ball bearings

Large-bore tapered-roller bearing performance and endurance to 2.4 million DN

The operating characteristics and experimental life estimates for 120.65 mm bore tapered roller bearings of two designs under combined radial and thrust loads were determined. A modified standard bearing design was tested at speeds up to 15,000 rpm. A computer optimized, high speed design was tested at speeds up to 20,000 rpm. Both designs were tested at a combined load of 26,700 N (6000 lb) radial load and and 53,400 N (12,000 lb) thrust load. Advanced helicopter transmissions which require the higher-speed capability of tapered-roller bearings also require higher temperature capability (ref. 2). Thus, materials with temperature capabilities higher than the conventional carburizing steels are required

Sold Downstream: Free Speech, Fair Use, and Anti-Circumvention Law

[Excerpt] “Here’s a hypo. Living in Asia, I purchased a shameful amount of music and movies, all legit purchases through reputable stores, HMV and Tower Records, but little of which will get reissued. I wanted to preserve my collection but software in the discs prevented me from ripping backup copies to my computer. Lacking the technological savvy to get around this software myself, I purchased and used a product to help me circumvent these controls. Discuss. Courts agree that copying the music and movies here is infringement but that fair use may provide a defense. However, courts do not agree as to whether or not fair use provides a defense when determining the liability of selling products that enable me to access and copy my CDs to my computer. This article examines a line of cases in the Ninth Circuit that hold that fair use or lawfulness of copying is irrelevant in calculating liability under the Digital Millennium Copyright Act (DMCA) and another line of cases in the Federal Circuit which hold that fair use should be relevant. In particular, this article argues that calculating fair use into the analysis is crucial in maintaining the balance between the First Amendment’s protection of free speech rights and copyright’s regulation of speech. Part I will outline the relationship between free speech rights and copyrights, noting the important role that fair use plays in keeping this relationship harmonious. Part II will outline the anti-circumvention provisions in the Digital Millennium Copyright Act and argue that these broad brush provisions chill speech. Part III will discuss two streams in the current law: first, the Ninth Circuit’s decisions 321 Studios v. Metro Goldwyn Mayer Studios, Inc.1 and Sony Computer Entertainment America, Inc. v. Divineo; 2 and, second, the Federal Circuit’s decisions in The Chamberlain Group, Inc. v. Skylink Technologies, Inc.3 and Storage Technology Corporation v. Custom Hardware Engineering & Consulting, Inc.4 Part IV will argue that the Federal Circuit’s approach to fair use is favored. However, an alternate analysis toward their conclusion would have more constitutional integrity. Namely, the DMCA, as applied to software, should be seen as a content-based restriction on speech and should not be read to prohibit circumvention of access controls where the circumvention would not constitute a copyright violation.

A review of Goerita (Trichoptera: Goeridae) : with description of a new species

Goerita Ross is restricted to the Appalachian Mountains and Allegheny Plateau of eastern North America. A new species is described, bringing the total in the genus to three. Keys to larvae and adults are presented, and the distributions of the species are recorded

Rolling-element fatigue lives of AISI 52100 steel balls with several synthetic lubricants

Rolling-element fatigue tests were run with three synthetic lubricants with and without antiwear additives and with a paraffinic mineral oil at race temperatures of 336 to 353 K (146 146 to 175 F). The five-ball fatigue tester was used with steel balls to evaluate the relative fatigue lives with each of six lubricant-additive combinations. The tests were run at 5,520 MPa (800,000psi) maximum Hertz stress, 10,000 rpm shaft speed, and 30 deg contact angle. The lubricants tested have similar kinetic viscosities at 372 K (210 F) ranging from 0.034 to 0.089 sq cm/sec (3.4 to 8.9 cS). At these conditions, the mode of failure in the five-ball fatigue tester was classical subsurface rolling-element fatigue. The baseline for comparison of fatigue life was the paraffinic mineral oil without additives. The effects of the synthetic lubricants and their additives, which are useful for boundary lubrication, oxidation or foam inhibition, were evaluated

Lubrication of rolling-element bearings

The lubrication of rolling element bearings is surveyed. Emphasis is on the critical design aspects related to speed, temperature, and ambient pressure environment. Types of lubrication including grease, jets, mist, wick, and through the race are discussed. The historical development, present state of technology, and the future problems of rolling element bearing lubrication are discussed

Comparison of predicted and experimental thermal performance of angular-contact ball bearings

Predicted bearing heat generation and bearing temperature were verified by experimental data for ball bearings over a range of sizes, shaft speeds, and lubricant flow rates. The computer program Shaberth requires, as input, a factor which describes the air-oil mixture in the bearing cavity for calculation of the ball drag contribution to bearing heat generation. An equation for this lubricant percent volume in the bearing cavity was derived and appears to be valid over the range of test conditions including bearing bore sizes from 35 to 167 mm and shaft speeds from 1.0 to 3.0 million DN

Complex hyperbolic free groups with many parabolic elements

We consider in this work representations of the of the fundamental group of the 3-punctured sphere in ${\rm PU}(2,1)$ such that the boundary loops are mapped to ${\rm PU}(2,1)$. We provide a system of coordinates on the corresponding representation variety, and analyse more specifically those representations corresponding to subgroups of $(3,3,\infty)$-groups. In particular we prove that it is possible to construct representations of the free group of rank two \la a,b\ra in ${\rm PU}(2,1)$ for which $a$, $b$, $ab$, $ab^{-1}$, $ab^2$, $a^2b$ and $[a,b]$ all are mapped to parabolics.Comment: 21 pages, 11 figure