Timken Initiates New Rotating Products Beyond Bearings to Talk about Bearing Efficiency

a few years ago, an automaker customer sitting opposite Ryan Evans made an unusual request. "He wants to know how we can accurately predict the power consumption of our bearings in their applications." Evans said. He is currently responsible for the bearing research and development of Timken Company. Timken's SYBER bearing performance prediction software can be used not only for bearing selection analysis, but also for estimating torque and power consumption, but for the customer's application, the customer seems to want to obtain more reliable prediction results.

bearings involves many disciplines-from fluid mechanics to solid mechanics, thermodynamics and heat transfer, etc. Bill Hannon, a product-based scientist at Timken, said: "This is to study how the properties of substances (whether steel or liquid) change when they encounter high pressure, high speed and high temperature in frictional contact."

For example, a tapered roller bearing may contain 15 rollers, which are the contact points. To calculate torque, you must consider how all these different contact points will respond to the load and speed of a specific application. For example, whether the material will bend under these contact points, or whether the lubricating oil between them will be subject to shear effect.

"It will be a daunting job to consider all the above factors and then get the total power consumption or torque performance of the bearing." Evans said.

Beyond Bearing Talking about Bearing Efficiency

However, similar customer demands continue to emerge. "Our customers are under pressure to improve fuel efficiency." Evans said. From tractors to delivery trucks to luxury cars, manufacturers of all kinds are turning to electric vehicles. In order to minimize the weight of the battery and maximize the mileage of the vehicle, they must minimize the friction at each point in the machine.

bearing efficiency is one of them, and Timken started designing energy-saving bearings decades ago. In 1975, the American Enterprise Average Fuel Economy (CAFE) regulations required higher fuel efficiency standards. Timken's fuel-saving bearings played an important role in the design of traditional and hybrid vehicles.

Timken's senior product development engineer, has directly cooperated with customers on the design of power transmission systems and assisted in the development of Timken's oil-saving bearings (ePDFE).

said: "At Timken, we have always paid attention to the friction and energy loss during the rotation of the bearing. In order to further improve the bearing efficiency, we need to understand the whole system, including the customer's lubrication system."

understand the properties of fluids

"Customers want to use lighter weight and lower viscosity lubricants, but this will cause hardware problems." Sadinski said. In order to help customers optimize the bearing lubricant combination to achieve the highest efficiency, the Timken team needs to combine bearing technology with rheological research. Rheology is a branch of physics that studies the flow of liquids.

Hannon said: "When I touch some lubricating oil on my hand, I can rub my fingers to feel it. I think it is soft and light. But in the bearing, this is not the case at all. When the rolling element meets the raceway, the contact pressure is very high, the oil film is very thin, and the lubricating oil will almost become solid."

In other words, as the acting pressure, temperature and shear rate of the contact point increase to extreme levels, the viscosity or flow resistance of the lubricating oil will change strangely. To make matters worse, the petrochemical industry has changed dramatically over the past decade. "There used to be only a few viscosity regulators, but now there are hundreds." Hannon said.

to predict bearing efficiency, it is necessary to understand the exact properties of liquid, lubricating oil or grease in each application. Hannon said that in an ideal environment, application engineers can measure lubricant performance at a pressure of 3,000 MPa or 435,000 pounds per square inch.

said: "No one can do this. There are few laboratories in the world that can measure values greater than 1,000 MPa."

In addition, he said, engineers also need to understand how the viscosity of lubricating oil changes with the acting pressure, temperature and shear force. "We know that there are only three places in the world that can do this." Hannon said: Georgia Institute of Technology (Georgia Tech), the French National Institute of Applied Sciences (INSA) in Lyon, France, and now Timken.

a laboratory for scientists to observe grease

Hannon said that Timken's rheology laboratory is based on the theory that enables the company to use physics principles to improve torque prediction models. To test this theory, the research and development team asked Georgia Tech researchers to measure the viscosity of the two oils. The Timken researchers then entered the measurements into their model, and it turned out that they could indeed make more accurate bearing efficiency predictions.

"At that moment, we decided to invest." Hannon said. Today, Timken's rheology laboratory is equipped with two falling viscometers, which can measure viscosity and density under various pressures and temperatures. With the Kuait viscometer, our team can also measure the response of lubricants to high shear rates.

Hannon also said that the laboratory also has some very practical equipment, including: a Fourier transform infrared spectrometer that can help our team identify unknown fluids; An energy dispersive X-ray spectrometer can help our team identify components in the liquid that are worn to the equipment. A Karl Fischer titration device can detect moisture in oil; And some other "equipment that allows us to analyze grease".

Let Theory Push Models

using these devices, Hannon and Sadinski can measure individual fluids and use the data to build new mathematical models that allow them to predict an infinite range of conditions in multidimensional space.

"We have returned to the principle of fluid mechanics, so it is the theory that led to the establishment of our model." Hannon said. Studying things at the first principle level allows our team to predict friction, not just measure friction. At the same time, he believes: "With the help of the rheology laboratory, we will be able to get closer to reality and reduce assumptions, which in turn will bring our simulations closer to practical application conditions."

Evans said: "These new measurement technologies allow us to measure lubricating oil in an unprecedented way. We insert these data into a mathematical model, and then we can help us predict the performance of the fluid in the bearing under high pressure and high shear conditions. This information enables us to better predict the overall torque or power consumption performance."

from Laboratory to Customer Design Table

After the research and development team added the new mathematical model to Timken's SYBER system, application engineers around the world can make more accurate power consumption estimates. "SYBER helps us get information and knowledge from the laboratory and then pass it on to customers." Evans said.

Hannon and Sadinski have been in close contact with lubricant manufacturers, who are increasingly accepting various fluids. Hannon said: "In this way, it may be possible to use lubricants and bearings in the future. In the rheology laboratory, we are sure that this can be done, so now we are all working hard for this, including lubricant manufacturers, bearing manufacturers and customers."