Specialist power transmission supplier JBJ Techniques Limited, of Redhill, Surrey, England were recently contacted by the staff of Bloodhound SSC R&D engineering team to solve a problem on the fuel pump test rig. JBJ Techniques had worked with various team members in the past and this previous experience made JBJ an easy choice to assist with this project. The scope of supply was to produce a suitable drive coupling with a maximum diameter of 160 mm, capable of transmitting 550 Nm @ 10,000 rpm, with as short an assembly as possible, and at the same time be able to accept misalignment within the drivetrain.

Asymmetric tooth gears and their rating are not described by existing gear design standards. Presented is a rating approach for asymmetric tooth gears by their bending and contact stress levels, in comparison with symmetric tooth gears, whose rating are defined by standards. This approach applies finite element analysis (FEA) for bending stress definition and the Hertzian equation for contact stress definition. It defines equivalency factors for practical asymmetric tooth gear design and rating. This paper illustrates the rating of asymmetric tooth gears with numerical examples.

Dale Renner, CBS and sales representative at Bearing Headquarters Co., explains how his bearing expertise helped solve a customer’s problem and saved significant downtime and cost.

In 1941, the federal Aircraft Engine Research Laboratory set up shop in Cleveland, Ohio. This year, and several name changes later, what is now the NASA Glenn Research Center celebrates its 75th anniversary. As part of the year-long festivities, Glenn’s adjunct Lewis Field main campus will be open to the public May 21 and 22, and Plum Brook Station in Sandusky, Ohio will hold its open house June 11 and 12.

There’s nothing quite as satisfying as scoring a goal. Here at Power Transmission Engineering, our goal is to provide you with as much relevant educational and technical material as possible, and every issue we strive to cover the subjects of power transmission and motion control from as many different angles as possible, so that no matter your job title, and no matter your industry, if gears, bearings, motors and related components are important to you, we’ve got you covered.

News from around the industry

The performance of high-speed helical geartrains is of particular importance for tiltrotor aircraft drive systems. These drive systems are used to provide speed reduction/torque multiplication from the gas turbine output shaft and provide the necessary offset between these parallel shafts in the aircraft. Four different design configurations have been tested in the NASA Glenn Research Center, High-Speed Helical Geartrain Test Facility. The design configurations included the current aircraft design, current design with isotropic superfinished gear surfaces, double-helical design (inward and outward pumping), increased pitch (finer teeth), and an increased helix angle. All designs were tested at multiple input shaft speeds (up to 15,000 rpm) and applied power (up to 5,000 hp). Also two lubrication, system-related, variables were tested: oil inlet temperature (160–250° F) and lubricating jet pressure (60–80 psig). Experimental data recorded from these tests included power loss of the helical system under study, the temperature increase of the lubricant from inlet to outlet of the drive system and fling-off temperatures (radially and axially). Also, all gear systems were tested with and without shrouds around the gears.

Our “Batten Down The Hatches” call proved timely as the market sold off by about (10 percent) before staging a partial recovery

Power Transmission Engineering is collaborating with the Bearing Specialists Association (BSA) on a special section within the magazine. Bearing Briefs will present updated reports on bearing topics for each issue in 2016. Complimentary access to all BSA Bearing and Industry Briefs is available on the BSA website at www.bsahome.org/tools.

During the past 10 years, the PM industry has put a lot of focus on how to make powder metal gears for automotive transmissions a reality. To reach this goal, several hurdles had to be overcome, such as fatigue data generation on gears, verification of calculation methods, production technology, materials development, heat treatment recipes, design development, and cost studies. All of these advancements will be discussed, and a number of vehicles with powder metal gears in their transmissions will be presented. How the transmissions have been redesigned in order to achieve the required stress levels while minimizing weight and inertia, thus increasing efficiency, will also be discussed.