Sakai America, Inc. | tel 800.323.0535
Asphalt Technical Product Information
Sakai vibratory asphalt rollers include the following unique designs:
4000 VPM Vibration Frequency – The rate of frequency of a vibratory roller is determined by the speed at which the hydraulically-driven vibration motor can rotate. In addition, and more importantly, it is determined by the design of the oil-bath-lubricated vibration shaft bearings, which must accept the faster speeds without deformation. At ConExpo 1999, Sakai introduced an entirely new design in their vibration systems. These new systems have been field-proven to accept the higher 4000 vpm speeds without the failure rates experienced by competitive machines that simply crank up the speed without concern for overheating of the system.
Counter-rotating Drum Weights – Unlike most competitive rollers, Sakai counter-rotates their drums. This concept provides a smoother surface finish by eliminating bow wave build up and the resultant hairline cracking created by a unidirectional rotation. Yet another concept critical to the success of the vibratory asphalt roller is the manner in which the manufacturer chooses to rotate the eccentric weights in both drums. Typically, most manufacturers rotate their weights together, in the same direction at the same time. This design causes forces to be generated in all directions including laterally, at which time they can create a bow wave in front of the drums. This bow wave, in turn can cause hairline cracking of the mat.
Following many years of research on the test track as well as in the field, Sakai chooses to counter-rotate their eccentric weights. This counter-rotation causes the drum to vibrate vertically while canceling out the lateral forces that can cause bow waves and cracking. Triple-filtered water spray systems, on-board back-up pumps, poly water tanks and twist-off bronze (not plastic like the competition) spray nozzles keep Sakai asphalt rollers running longer – uptime for the bottom line.Oil and water don’t mix. We all know that. It is important that the asphalt under compaction doesn’t stick to the steel drums of the roller. To prevent this from happening, all manufacturers employ a water spray system that keeps both drums wet while on the mat. The challenge to the manufacturer is to design the system that keeps working no matter what, for a failed spray system will quickly shut down an asphalt paving job. Sakai introduced a number of preventive measures to keep their rollers on the job. One is a triple-filtered spray system that keeps debris out of the water path to the drum. These filters are easy to access and easy to clean, ensuring on-the-job availability at all times.- Twist-off Spray Nozzles – Simple twist-off bronze spray nozzles at the spray bars are easy to clean and replace virtually on the run. No need to shut the roller down.
- Pumping System – In addition to the filtration system, Sakai employs a back-up pumping system that will immediately take over if the primary system fails.
- Rubber Mats – Keep debris from sticking to the drum while at the same time ensuring that the water spray is spread evenly across the surface of the drum. These spring-loaded mats are easy to disengage for clean-out and re-engage for use.
- Comfortable Bucket Seats – Offer excellent visibility and a great place to go to work. On larger Sakai rollers, the seat and controls are mounted on a rotating platform that permits a clear view of the drum edges. Machined drum surfaces and rounded edges provide a concentric rolling drum for a mark-free asphalt mat.