Donald E. Bently

Donald E. Bently (October 18, 1924 – October 1, 2012) was a globally recognized authority on rotor dynamics and vibration monitoring and diagnostics, and an American entrepreneur, engineer, and philanthropist. He founded Bently Nevada Corporation in October, 1961, where he performed pioneering work in the field of instrumentation for measuring the mechanical condition of rotating machinery. He designed the first commercially successful eddy current proximity transducer. It became the de facto standard when the American Petroleum Institute adopted the proximity probe as the device for measuring acceptable shaft vibration during factory acceptance testing of centrifugal compressors.

He was the company's president and later CEO until it attained $250 million in annual sales, when he sold it in February, 2002 to GE Energy. In 2017 GE merged it into Baker Hughes. The company continues to design, manufacture, and market vibration monitoring and diagnostic products and services as a subsidiary of the Baker Hughes Company. Following the sale of Bently Nevada, Bently remained active in his other family-owned businesses representing a diverse range of interests including rotordynamics, agriculture, biofuels, real estate, externally pressurized fluid bearings, and machinery diagnostics.

Personal life

Bently was born in Cleveland, Ohio, to Oliver and Mary Evelyn Bently. He had an older brother Oliver and a younger sister Alice. His great-grandfather Benjamin Nye, one of Muscatine County's first settlers, built the Pine Creek Gristmill in 1848. It is now a historic landmark in Wildcat Den State Park near Muscatine. Bently's father Oliver was a veteran of World War I and a farmer. Oliver bought a bowling alley when Don was 14, and Don learned to set pins. He graduated from high school in Muscatine and was drafted into the U.S. Navy during World War II. He served with the 141st Naval Construction Battalion (NCB) as a Seabee from August 1943 to April 1946. His brother Oliver served in the U.S. Army Air Force in the troop carrier command from 1943 to 1946.Oliver Bently The Muscatine Journal Muscatine, Iowa. May 14, 1997. Page 5

The 141st NCB was stationed at Hilo, Hawaii. It earned battle stars for service in Luzon, Leyte, Saipan, and Tinian. Bently made four major amphibious landings during the war. In June, 1945, all of the Battalion's units but Bently's company were detached for service on Samar island in the Philippines. His company of 224 men was instead ordered to Kwajalein Atoll, Marshall Islands, where it arrived on May 24. The unit (known as ACORN: for Aviation, Construction, Ordnance, Repair) constructed a major aviation facility on Kwajalein Atoll. The facilities were later used as a command center to prepare for Operation Crossroads.Dvorak, Gregory. "The 'Martial Islands': Making Marshallese Masculinities between American and Japanese Militarism." The Contemporary Pacific Journal, 18(1) January 2008. In his free time, Bently began taking extension courses from the University of Iowa. His officer told him not to bother: "You'll probably be dead within the year anyway." The unit was preparing for the invasion of Japan when the Japanese surrendered on August 15, 1945. The 141st NCB was inactivated on January 2, 1946.

He returned to Muscatine and attended the University of Iowa. While a student, he married Verna Francis Holt on July 3, 1948, in Muscatine.Bently - Holt Quad-City Times Davenport, Iowa. July 6, 1948. Page 6.Holt / Bently Wedding is Solemnized in Iowa City The Muscatine Journal July 5, 1948. Page 6 Upon graduation in 1949, he received a Bachelor of Science degree in Electrical Engineering, after which he earned a master's degree in Electrical Engineering in 1950. Bently worked as the lead azide and mercury fulminate assembly line primary detonator engineer at the Iowa Ordnance Plant in Burlington, Iowa.

In 1950, he moved to California. He worked at the Rocketdyne division of North American Aviation in California for three years during which he did graduate-level coursework at UC Berkeley and UCLA. At Rocketdyne he learned about electronic sensing technologies for aircraft control systems. He thought the technology had commercial applications in other fields and received permission to use it in his own endeavors. In 1956 Don left Rocketdyne and began experimenting with eddy-current sensing technology and formed Bently Scientific Company. He manufactured and sold eddy-current products via mail-order out of his garage in Berkeley, California.

In 1960 he bought land in Douglas County, Nevada. In 1961, Bently relocated his company to Minden, Nevada, and incorporated it as Bently Nevada Corporation with three people. A year after relocating to Nevada, he married Susan Lorraine Pumphrey on October 5, 1962. They adopted a son Christopher and were divorced in 1981. Bently died on October 1, 2012, at his home in Carson Valley, Nevada. He was 87.

Founder of Bently Nevada

Bently began selling instrumentation from his garage via mail order in 1955. He organized his first business as Bently Scientific Company in Berkeley, California, in 1956. He moved the company to Minden, Nevada in 1961 and incorporated it as Bently Nevada Corporation with three employees. In 1958, a team from Pepperl+Fuchs had invented an inductive eddy-current sensor as a replacement for a mechanical switch. But Bently's company was the first to successfully commercialize eddy-current proximity transducers, non-contacting displacement sensors measure vibration in high-speed turbomachinery. This type of electronic sensor is typically used to measure very small distances between the tip of the sensor and a conductive surface, such as rotating shaft. The displacements measured are extremely small, typically only several thousandths of an inch. Bently's application of eddy-current sensor technology was the foundation of an entire industry. Bently could be extremely demanding. He had high standards and did not compromise. He wrote, "Early in my career I decided that I would be absolutely true to my principles. This stand has led me occasionally to lose business, and sometimes lose employees. In the end, however, I have never regretted adhering as closely as I know how to a set of timeless principles. As I built my company, I demanded of my employees this same dedication to principle."Bently, Donald E. Core Values The Bent of Tau Beta Pi. 1999. page 18 One employee was his executive assistant for 17 years, but he was well known for dismissing assistants with whom he did not get along.

The eddy-current proximity probe pioneered by Bently became the de facto standard for the industry. In 1970 the American Petroleum Institute designated the proximity probe as the measurement device for measuring acceptable shaft vibration during factory acceptance testing. It added this as a requirement to its standard for turbomachinery acceptance testing and machinery protection.Sabin, Steve A New Edition of API 670 Orbit. March 2001. page 32. The eddy-current proximity probe became the preferred method for assessing vibration and overall mechanical condition on large turbomachinery employing fluid bearings.

Bently Nevada manufactures and sells asset protection and condition monitoring hardware, software and services for industrial plant-wide operations. Bently Nevada opened its first international office in 1969 in the Netherlands. It gained recognition as the leader in the field. The company grew substantially over the years until in 2002 it had 1,200 people at its headquarters in Minden, Nevada, 2,100 employees worldwide, 100 offices in more than 40 countries, and global sales exceeding US$235 million. In January 2002 at age 78 Don Bently sold the business to GE Energy for between $600 million and $900 million. Its products are used world-wide to monitor the mechanical condition of rotating equipment in a variety of industries including oil and gas production, hydroelectric, wind, hydrocarbon processing, electric power generation, pulp and paper, mining, water and wastewater treatment.

Other business interests

Bently founded or owned a number of other businesses.

Bently Pressurized Bearing Company

The bearing company manufactured a bearing that can hold a rotating axle in place. The technology injected highly pressurized air between the bearing and the rotating machinery, preventing the axle from touching the bearing, virtually eliminating friction. Bently Pressurized Bearings was sold in 2014 to New Way Air Bearings.

Bently Rotordynamics

In 1981, Bently established a pure research organization called Bently Rotordynamics Research Corporation (BRDRC or "Birdrock"). BRDRC's objective was to conduct rotordynamic research, furthering the knowledge of rotating machinery behavior, modeling techniques, and malfunction diagnostic methodologies. Its mission was considered complementary to Bently Nevada, with BRDRC focused on understanding how machinery behaved, and Bently Nevada focused on understanding and building instrumentation to measure machinery behavior.

BRDRC made a number of important contributions to the field of rotordynamics such as a better understanding of fluid-induced instabilities, advanced models for understanding shaft crack behavior, insight into rubbing malfunctions between stationary and rotating parts, and enhancement of the rotordynamic equations via introduction of a new variable lambda (λ) which denoted the fluid circumferential average velocity ratio and more accurately modeled hydrodynamic effects. Bently was personally responsible for many of these developments, publishing his work under the auspices of BRDRC. BRDRC also introduced several new data presentation formats, such as so-called "full" spectrum plots and "acceptance region" trend plots. Its research findings were published extensively in relevant technical journals, and the research that had practical commercial applications often found its way into the Bently Nevada product line. In 2002, BRDRC was sold along with Bently Nevada to GE Energy.

He founded RoMaDyn, a mechanical engineering services and diagnostics company.

Bently Agrowdynamics

Bently founded Bently Agrowdynamics, which focused on environmentally sustainable agricultural practices with crop, cattle, and compost production. Over more than two decades, Bently bought more than of agricultural land in and around Carson Valley, Nevada, part of the former Dangberg Ranch. He established Bently Ranch to raise beef cattle and alfalfa. Following his interest in sustainable energy, he began composting waste materials which he sold as soil amendments and premium compost blends. He built a bio-diesel plant in Minden and he sold the fuel beginning on September 30, 2008, through Bently Biofuels Outpost, a retail location in Minden. In 2018, they converted the store into Bently Ranch Butcher Shop, a retail outlet for their premium beef. The store was closed during the 2020 Covid Pandemic.

As president of Bently Agrowdynamics, Bently led reconstruction of Mud Lake Dam south of Gardnerville which had been damaged during the 1994 Double Springs Flat magnitude 6.0 earthquake. They replaced the long, 100-year-old earth-filled dam with a long rock-filled dam on a concrete foundation. The new dam was built slightly downstream of the original dam. It was completed in June 2000 at a cost of $7 million. The dam provides irrigation water to more than of land that are part of Bently Agrowdynamics’ South Ranch. The new dam not only improved the dam's resistance to earthquakes but helped protect the nearby community.

Founded ISCORMA

A significant amount of Bently's rotordynamic research efforts were about rotor dynamic stability. In 2001, he established ISCORMA, (International Symposium on Stability Control of Rotating Machinery), a bi-annual industry event. Bently was an active organizer and participant in all ISCORMA conferences until his death.

Work with NASA