Corporate / Founder

Donald E. Bently

Donald E. Bently - Chairman and Chief Executive Officer, Bently Pressurized Bearing Company

In addition to Bently Pressurized Bearing Company, Donald E. Bently owns a diverse portfolio of other businesses including:

Bently Tribology Services, Inc. (
Laboratory services for analyzing the condition of lubricants and hydraulic fluids.

Bently Agrowdynamics (
Progressive and sustainable agricultural practices with crop, cattle, and compost production on 38,000-plus acres in and around Northern Nevada's Carson Valley.

Gibson Tool & Supply (
Leading industrial tool distributor that serves metalworking and manufacturing customers throughout Northern Nevada.

Mr. Bently is perhaps best known as founder of Bently Nevada Corporation, the world's leading supplier of condition monitoring instrumentation and services, a $250 million business that he sold to GE Power Systems in January 2002. Mr. Bently served as Chairman and CEO until that time. He also founded Bently Rotor Dynamics Research Corporation, a wholly owned subsidiary of Bently Nevada, where the basic ideas for his bearing technology were pioneered along with numerous other contributions to the body of knowledge surrounding the behavior of rotating machinery and rotor dynamics.

Mr. Bently pioneered the first commercially successful eddy current proximity transducer and introduced its use to measure vibration and other critical parameters in rotating machinery. His visionary work in this area gave rise to an entire industry surrounding the use of vibration instrumentation to protect and diagnose machinery. The company he built – Bently Nevada Corporation – enjoys recognition as the world leader in its field. Today, he is actively pioneering fully lubricated, pressurized bearing technology – technology destined to be as influential as the proximity probe in revolutionizing rotating machinery.

Mr. Bently has made important agricultural achievements that contribute significantly to the quality of the environment in the Carson Valley. This has been accomplished through Bently Agrowdynamics, a business focused on environmentally sustainable agricultural practices and the innovative use of renewable resources. Key among these accomplishments is the use of efficient irrigation systems, including center pivot sprinkler and subsurface drip irrigation systems, to reduce water applications by over 33% when compared to conventional flood irrigation. In order to maximize the use of available water, Mr. Bently replaced the 100-year-old dam at Mud Lake Reservoir in 1999 with a synthetic membrane and concrete-lined dam designed to reduce seepage and to be reasonably earthquake resistant. Another reservoir is being constructed in 2003 that will provide Bently Agrowdynamics with 1,800 acre-feet of treated effluent storage. This fully lined reservoir will allow Bently Agrowdynamics to recycle municipal wastewater onto forage crops.

Mr. Bently is also committed to a sustainable crop fertility program. Bently Agrowdynamics uses municipal and agricultural wastes (biosolids, wood waste, cattle manure, and straw) to produce over 30,000 tons of high-quality compost and thousands of gallons of compost tea. These products are used on his fields, minimizing the use of synthetic fertilizers.

The Bently Agrowdynamics cattle herd is quickly gaining a reputation as one of the highest-quality commercial herds in the region. Use of advanced herd management techniques, such as electronic identification tags and computerized record keeping systems, and modern breeding technologies, such as artificial insemination and embryo transfers, ensure that the 1,200 angus and angus-crossbred cows produce the highest quality calves for sale to Midwestern feedlots.

In January 2003 Mr. Bently began leasing the River Fork Ranch along the Carson River from The Nature Conservancy. Bently Agrowdynamics is working with The Nature Conservancy to balance environmental improvements, including wildlife habitat and river stabilization, with hay production and cattle grazing. This lease appears to be the beginning of a long-term relationship, which may grow to include the addition of conservation easements on environmentally sensitive Bently Agrowdynamics properties.

Most recently, Mr. Bently has committed resources within Bently Agrowdynamics to research and development of biofuels. Crops such as canola and sunflowers, as well as waste vegetable oil from restaurants, will be used to make biodiesel (methyl esters), which can be used in conventional diesel engines with little to no modifications. Sudan grass and wheat straw can be converted to ethanol, replacing gasoline in automobiles. Such commitment to sustainable agriculture is key to his planning the longevity of the Bently Agrowdynamics organization.

Scientific and Technological Contributions

Mr. Bently is a globally recognized authority on rotor dynamics as well as vibration monitoring and diagnostics. He has authored or co-authored more than 140 papers and a book on these subjects and is the holder of two patents. His active research of rotor dynamics, his prodigious capacity for invention and imagination, and his business acumen have allowed him to make significant theoretical and practical contributions in this field including:

• Publication of Fundamentals of Rotating Machinery Diagnostics, a practical book covering the fundamentals of vibration and rotor dynamics. The text explains the use of modern root locus methodology and dynamic stiffness measurements for rotor stability analysis and includes a chapter on the control of fluid induced instability using externally pressurized bearing technology.

• Invention and commercialization of fully lubricated, pressurized fluid bearing designs that use axial, rather than circumferential, lubricant pressure profiles. This significantly reduces the attitude angle (a concept first introduced by Osborne Reynolds) resulting in a more stable bearing that completely eliminates fluid whirl instabilities. Misalignment, unbalance, and forward circular instabilities other than fluid whirl, such as fluid whip, may still exist, but can be addressed using other means. The bearing can use compressible and incompressible fluids for lubricants, and is applicable to radial, thrust, and combination radial/thrust applications.

• Derivation of lambda (l), the fluid circumferential average velocity ratio, as a result of joint scientific research with Dr. Agnes Muszynska.

• Co-development, along with Dr. Agnes Muszynska, of a vastly improved equation for direct and quadrature dynamic stiffness.

• Formulation of a shaft crack detection methodology for early warning of shaft cracks.

• Pioneering the use of vector acceptance regions and NOT 1X monitoring.

• Furthering modal perturbation testing methodology for rotating machines, building on the methods established by E.H. Hull.

• Together with Dr. Agnes Muszynska, explanation of the equation of fluid-induced instability.

• Promotion of the use of X-Y transducer configurations for machinery protection and diagnostics.

• Application of polar plotting and vector nulling to balancing and rotating machinery diagnostics.

• Popularization of orbit plots and development of tools and methodologies for interpreting these plots.

• Development and introduction of the Digital Vector Filter, along with Phil Hanifan and Mike Manchester.

• Development and commercialization of REBAM® technology, along with Roger Harker, to use high-gain proximity probe technology to directly observe the outer race of rolling element bearings and determine their mechanical condition.

• Use of the proximity probe – termed a Keyphasor® transducer – to provide a once-per-turn signal for precise timing measurements. This allows vibration phase lag to be quantified and helps in classifying machinery malfunctions based on their phase response characteristics.

• Introduction of X-to-Y terminology to describe direction of shape rotation, replacing the ambiguity and confusion caused by CW/CCW nomenclature used previously.

• Development of an online alignment device.

• Performing research on bearing/seal fluid-induced instability and rotor rub mechanisms.

• Pioneering the use of eddy current transducers for shaft modal identification.

• Introducing the "Wobulator" TK3-2 probe calibration instrument.

• Development of the rotor kit as a teaching, demonstration, and research tool.

• Development and commercialization of full spectrum data presentation format, showing forward and reverse precession components. Originally shown to Don Bently by Bill Foiles as something Bill called the "winding function."

• Application of Root-Locus methodology to rotating machinery diagnostics. Root-Locus theory was originated by Walt Evans and popularized by Dr. Katsuhiko Ogata in his text Modern Control Engineering, used in many college courses worldwide.

Awards and Accolades


• Received an Honorary Doctor of Science Degree from California Polytechnic State University, San Luis Obispo. This honor in recognition of distinguished leadership in the field of engineering and sustainable agriculture practices and exemplary support of Cal Poly.
Mr. Bently was asked by president Baker to say a few words following the degree conferral. He noted that he and Dr. Agnes Muszynska developed the equations for oil whirl and oil whip, therefore, there are no more papers on this troublesome topic.

• Received an Honorary Paul Harris Fellow from the Minden Rotary Club.


• Inducted as a lifetime ASME member.

• 2 December 2006, Grand Marshall for the "Holiday Magic" Parade or Lights presented by the Carson Valley Chamber of Commerce and Visitors Authority, between Lampe Park, Gardnerville, Nevada, and Minden Park, Minden, Nevada. Mr. Bently would never ever accept this honor again because he and Dr. Agnes Muszynska could not see anything.


• Awarded the University of Iowa Alumni Association's highest honor, the Distinguished Alumni Award. Granted on business and professional life accomplishments.

• Received Outstanding Alumni Award from Muscatine Junior College, Iowa.

• Inducted into the Muscatine High School Hall of Honor. Inductees are selected based on distinguished achievements after graduating from Muscatine High School, Iowa.


• Received College's Distinguished Service Award from California Polytechnic State University, San Luis Obispo.


• Became a member of the Nevada Future Farmers of America Foundation's Board of Trustees at the request of Senator Jacobsen upon his retirement.

• Received the Distinguished Nevadan Award from the University of Nevada, Reno.

• Fellow of the American Society of Mechanical Engineers (ASME)


• Inducted into the University of Iowa's Distinguished Engineering Alumni Academy for his "contributions toward personal engineering achievement, leadership, and service to the profession and society".


• ASME’s Frederick P. Smarro Award (co-recipient with Charles Bailey) for his "significant contribution to the discipline and practice of plant maintenance and/or engineering".

• Listed in

- Standard & Poor's Register of Corporations, Directors and Executives

- Marquis Who's Who in the West

- Marquis Who's Who in Finance & Industry

- Marquis Who's Who in Science and Engineering

- Marquis Who's Who in America

- Marquis Who's Who in the World


• ASME's R. Tom Sawyer Award for his "advancements in developing primary instrumentation and diagnostic tools, which have resulted in the advancement of gas turbine engine development and its continued successful operation".


• N.O. Myklestad Award bestowed by the Technical Committee on Vibration and Sound of the ASME Design Engineering Division.

• Carson Valley Citizen of the Year

• Bently Hall, within the Minden campus of Western Nevada Community College, is named after Mr. Bently in recognition of his commitment to higher education and his donation of 10 acres upon which the campus is built.

• Honored as a leading contributor to the "World Class…By Design" ASME Foundation campaign.

• Recognized by The Institute of World Politics as a board member and benefactor at a dinner for the grand opening and remodeling of the Marlatt Mansion in Washington, D.C. The Institute of World Politics is a graduate school of statesmanship, national security affairs, and moral leadership. It is dedicated to the defense of our country and civilization. Through Mr. Bently’s generosity, the Marlatt Mansion is now the Institute's headquarters.


• Recipient of Distinguished Research Award for achievements in the field of rotating machinery from the Pacific Center of Thermal Fluid Engineering.


• Made Foreign Member of the St. Petersburg Academy of Engineering in Russia.

• Honored as "Visiting Scholar of Tsinghua University" in Beijing, China.

• First person to receive the Vibration Institute's DECADE Award, commemorating the second decade of its operation.

• Inducted into the Junior Achievement of Northern Nevada.


• Honored as Nevada's outstanding inventor by the Nevada Innovation and Technology Council.


• Received four battle stars while on an amphibious landing team in the Pacific as a member of the U.S. Navy Seabees during World War II.

Educational and Professional Credentials

Mr. Bently is a Registered Professional Engineer in Electrical Engineering in Nevada (#1591) and California (#5242). He is a senior member of IEEE and a member of ASME; he is a member of honorary fraternities Sigma Xi, Eta Kappa Nu, and Tau Beta Pi; he is also a member of the social fraternity Sigma Alpha Epsilon (Iowa beta chapter).

Mr. Bently received a Bachelor of Science Degree in Electrical Engineering (With Distinction) in 1949 followed by a Master's Degree in Electrical Engineering in 1950 from the University of Iowa, Iowa City. He has done graduate work at the University of California at Berkeley, and in 1987 was awarded an honorary Doctorate in Engineering from the University of Nevada, Reno. He received an honorary AA Degree from Western Nevada Community College in 1998.

Donald E. Bently (email Don), CEO, Bently Pressurized Bearing Company

Top of Page