Lubrication-free bearings

Elastomeric bearings used in helicopters to handle loads and accommodate motion may start showing up in farm implements. These high-tech bearings require no lubrication or maintenance. They are widely used in helicopters where heavy dust and sand cause excessive wear. Traditional spherical bearings used in helicopters in desert locations must be replaced every 150 hrs., whereas the elastomeric bearings will last up to 3,000 hrs., according to Bob Michael of the Lord Corporation, a manufacturer of the bearings.

Industrial versions of the elastomeric bearings may be used in ag machinery in the next few years. However, not every bearing in farm implements may be replaced. The elastomeric bearings are best used in applications for carrying a moderate to high load and moderate motion. The bearings can handle torsion and cocking motions as high as ±45°.

The elastomeric bearing uses alternating layers of elastomer and steel shims (laminated sections) to create a very small piece that handles large loads. Several configurations are available and will fit in suspension components, end joints and bushings, suspension links, and spherical, elliptical and cylindrical bearings.

A big advantage of the bearings is that they require no maintenance or lubrication. Fittings, seals, retaining rings and grease lines are eliminated. Dust and dirt do not penetrate them, adding to their longevity. They simplify joints because a single bearing replaces several traditional bearings. They also create less noise and vibration than a steel bearing produces.

Manufacturers of agricultural equipment are interested in these bearings, Michael says, because they reduce system costs, require no maintenance and have increased durability.

The bearings were first developed nearly 70 years ago for use in large structures such as bridges and buildings. In the 1970s, the technology moved into the helicopter rotor industry. As the cost of producing the bearings goes down, more industrial markets open up, including the agricultural machinery industry.

For more information, go to www.lordcorp.com.

Harnessing brake energy

In a few years, farm trucks may be equipped with energy recovery systems that take braking energy, store it and then use it for acceleration of the vehicle. The systems can improve fuel efficiency, reduce exhaust emissions and extend brake life, especially on vehicles that do a lot of starting and stopping.

Eaton Corporation is developing such a system called a Hydraulic Launch Assist (HLA). “The HLA system takes energy that normally is wasted as heat by the friction brakes of a vehicle and saves it hydraulically to use later,” explains Brad Bohlmann, Eaton business development manager. “You don't have to pay to charge up the HLA system because you've already spent the money to accelerate the vehicle to a certain speed. When you do the braking, the HLA system captures the energy that normally is wasted. So I like to say that the HLA system captures energy when it is free and gives it back when it has the most value.”

Eaton is developing the systems for on- and off-highway vehicles, particularly trucks such as garbage and delivery trucks that stop many times a day. The system has been installed in a Ford Mighty F350 Tonka concept pickup. Tests show the HLA system will accelerate the F350 to 25 mph without engine power, Bohlmann says. The system is completely recharged in a single stop from about 30 mph.

The HLA system works especially well in vehicles that travel at road speeds. Vehicles moving at slow speeds do not have a great amount of kinetic energy when braking even if the vehicle is massive, Bohlmann explains. A vehicle moving at 10 mph has only one-fourth the kinetic energy of the same vehicle traveling 20 mph. “That's why on-road vehicles are attractive now because of the higher speeds,” Bohlmann says.

As HLA systems become commercially available and are produced in greater numbers, the cost of manufacturing will go down. At that point, farmers may be able to add the HLA system to pickup trucks or other farm vehicles. The system includes 10 gal. of hydraulic fluid that is held in low- and high-pressure accumulators. It is installed in a vehicle's driveline between the transmission and the rear axle.

To learn more about Eaton, visit www.eaton.com.

Precise sensors

Some new ag equipment, such as Bobcat's Toolcat, is equipped with the latest in sensor technology. In the Toolcat, rugged magnetic sensors installed on the bearing assembly detect position and speed. The information is fed by wire to the Toolcat's control system, helping coordinate the vehicle's all-wheel steering. The sensors are manufactured by Timken, which offers a wide range of sensors that make vehicles, such as farm equipment, operate more efficiently.

The new magnetic sensors offer high resolution while working in harsh environments and very small spaces. More off-road machinery will be equipped with small but powerful sensors as technology improves.

John Santos, team leader for Timken's intelligent products and systems, says the company also offers a new wireless sensor called StatusCheck. This inexpensive sensor can be used in a number of applications to monitor bearing health and machine condition such as temperature and vibration.

For more information about Timken, visit www.timken.com.