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Forestry Markets

Wood Chipper

Type 2 Power Take-off on side loading wood chipper.

Forestry is the management of forest land for harvesting, conservation, and recreation. Whether a wood chipper, grinder, or yarder, WPT has a PTO, pump drive, clutch, or brake to suit the application. Since WPT’s products are designed to operate for extended hours in challenging environments, it is no wonder we are a preferred supplier for many forestry equipment OEMs.

Portable, tracked, stationary, and truck-mounted wood chippers and grinders are used in the forestry industry to help manage land by clearing away excess brush and timber. They can also be used to process the trees into biomass for energy production or wildfire control. Some of WPT’s leading products in the mobile wood chipper market are the Power Take-off (PTO), pump drive, and industrial brakes and clutches.

The PTO attaches to the rear of the diesel engine and acts as a mechanical connection and disconnect between the engine and chipping drum. The Pilotless™ series of PTOs is the latest offering from WPT and provides up to a 70 percent increase in belt load capacity and other performance and maintenance-centered enhancements. The PTOs are available with the standard over-center mechanical engagement or the innovative Over-the-Shaft (OTS) hydraulic or pneumatic actuated version. The Pilotless™ Mechanical is geared toward cost-conscious applications while providing the reliability expected of WPT products. The Pilotless™ OTS, when paired with the WPT Hydraulic Power Unit, provides remote engagement options and is self-adjusting for wear.

The WPT Automotive and GM-style PTOs were specially designed for the smaller gasoline engine-driven chippers and grinders. To keep the actuator linkage free from debris and critters, the Automotive and GM-style PTOs utilize an internal linkage system. They are ensuring that these things do not interfere with performance. When it comes to maintenance, the easy adjustment feature of both the Automotive and GM-Style PTOs makes this a snap.

Mechanical Power Take-off on chipper

This tracked wood chipper features Mechanical Power Take-off.

The WPT Type 2 and Type 1 PTOs are the next step in rugged performance for wood chippers, tub and horizontal grinders. These Type 2 PTOs are designed to provide reliable hydraulic or pneumatic actuation and industry-leading belt loading and power transfer capabilities, all in a compact package. There is only one option for most heavy-duty belt-driven equipment: the WPT Type 1 PTO. The straddle bearing setup positions the centerline of the belts between a pair of oversized bearings for maximum capacity, life, and power transfer. The Type 2 and Type 1 PTOs also come standard with WPT Heavy Duty frictions discs.

A companion to the Type 2 and Type 1 PTOs is the WPT Python™ Hydraulic Clutch Control. Designed from the ground up with forestry suppliers in mind, the Python™ is an all-one solution for remotely engaging high-inertia machines like wood chippers and grinders. Features include: J1939 CANbus compatibility, self-contained, compact design, patented electronic engagement, overspeed protection, and improved life of the attached equipment.

Another in-demand product in the mobile chipper and grinder business is the WPT Pump Drive. These units are positioned between the engine and the PTO to provide hydraulic pump mounts for auxiliary equipment like grapples, loaders, tracked drives, winches, or other equipment. WPT also provides the input coupling to ensure the drive train is smooth as well as durable. The Pump Drives come in four different models depending on the requirements of the equipment and provide up to eight additional pump mounts for versatility.

Another pair of products that are used, albeit not as prominently, in both mobile and stationary wood chippers are the WPT Low Inertia Clutches and Brakes. The PTO clutch is attached to the engine’s flywheel in a typical mobile wood chipper application. However, it is possible to move the clutch to the drum of the chipper. Using a WPT Low Inertia High Torque clutch in this arrangement provides benefits such as slower engagement speeds for the clutch, a larger friction surface area, and less maintenance. Stationary wood chippers can employ the same clutching options described above but will often have a Low Inertia Spring Set brake to stop the drum in the event of an emergency or to decrease the spin-down time for maintenance operations. When paired together, these two products provide an outstanding performance package.

Yarders have a long history in the cable logging business. Early machines were powered by steam and transported through the terrain on specialized railroads called dummy lines. Today, the modern yarder is often diesel powered and can traverse the hilly landscape with the help of a hydraulic tracked drive. The yarder is essentially a series of high-capacity winches used to relocate material from the woods to a designated landing zone for processing or further transportation. Typical products used in the yarder machines are the Low Inertia Clutch, Low Inertia Brake, and Water Cooled Brake.

The WPT Low Inertia Clutch is used on the yarder to transfer the power from the engine to the winches. There can be up to 12 winches on the largest yarders. The Low Inertia Brakes are used to hold the line in place or slow the carriage’s descent during transport. This constant tension applied to the line creates tremendous energy in the brake; therefore, a WPT Water Cooled Brake will be outfitted to the yarder. The Water Cooled Brake is a heavy-duty product that provides the torque to slow or stop the load and has uniquely designed high-flow water jackets to transfer the thermal load into an external cooler or tank.

In the end, with products like the innovative Pilotless™ series, easy maintenance GM® and Automotive-style PTOs, the rugged Type 2 and Type 1, the versatile Pump Drive, the high-performing Low Inertia Clutch and Low Inertia Brake, and the heavy-duty Water Cooled Brake, WPT Power will have the product and the solution.

For more information on any products listed above, don’t hesitate to contact WPT Power Applications Engineering or WPT Power Customer Support.

Clutches and Brakes for Yarders

WPT Power is the only manufacturer who produces the four most common clutch and brake designs used on yarders.