Burnishing is the process of wearing-in the clutch brake. Clutch brakes are commonly used on lawn and garden equipment such as residential and commercial mowers. They are also used on portable sawmills, stump grinders, and other engine-driven outdoor power equipment that benefits from remote clutch engagement and the safety of a brake to slow the rotating blades upon clutch disengagement.

Burnishing comes from dynamic engagements of the clutch and brake. Inherently in the engagement process, there is momentary slipping of the friction surfaces. For the clutch, this slipping period occurs until the rotor and output have matching rpm and there is full torque transfer. For the brake, the slipping occurs until the output comes to a complete stop. During these initial cycles, the high spots on the friction surfaces are worn down and coefficient of friction increases, leading to higher clutch and brake torque.

It is important to follow the original equipment manufacturer's recommendation for burnishing. It is determined by the manufacturer if the clutch on the machine needs burnishing or not. Every machine is different. Also, the operating conditions can vary as well. Generally speaking, it is not advised to mow high, wet grass before your clutch is fully burnished. The risk is that your clutch may be overloaded causing excess slippage and perhaps permanent damage to the clutch friction surfaces.

As a rule of thumb, PTO clutch brakes are fully burnished to achieve full torque capability after about 20-40 cycles. It is important not to cycle the clutch too quickly because there is heat generated during the burnishing process and the clutch needs time to dissipate the heat. Some OEM's may burnish the clutches before shipping to their customers, while others will tell their customers to do the burnishing themselves, if full torque is needed for their application. For the same reason, Ogura does not fully burnish the clutches at our factory because not everyone needs the full torque transfer capability.

Ogura GT series PTO clutch-brakes are made in a variety of configurations and typically mount on gas and diesel engines rated up to 40 HP. Bore sizes match the typical engine shaft sizes. Pulley sizes can vary based on machine requirements. Some have hub outputs to mount your own pulley, sprocket or coupling half. Clutch torque is rated up to 400 lb-ft on the larger units. These clutches typically operate on 12 or 24VDC.

Benefits of using an Ogura PTO clutch brake:

• Long life
• Safety
• Fuel and energy savings
• Built for outdoor operation
• Many years of proven success
• For use with operator presence controls
• Available with a soft start controller
• Custom designs available based on minimum order quantities

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