Satellite roller screws, an upgrade on ball screws? "I need more performance from my existing linear device." "My hydraulic linear actuation system is a major part of my maintenance schedule" ! "My ball screw is failing prematurely due to high duty cycle". ! "I have reached the boundary of performance from my existing ball screw but have no way of increasing its dimensions within the current design" ! Sound familiar ? These are some of the questions being asked by design engineers or maintenance engineers when coming to ABSSAC in search of a linear technical assistance. The satellite roller screw program, exclusively available from ABSSAC Limited, is proving to be a formidable advantage in the linear technology sector. With a traditional ball screw design, the captivated ball bearings transfer the load between the screw and nut as they recirculate in the ball nut housing. To increase the load capacity of the ball screw you have to either increase the number of ball bearings in the nut housing, for example by doubling the actual ball returns or alternatively you have to increase the amount of times the ball bearings recirculate within the ball nut housing . Of course the final option is to choose a larger, more expensive ball screw !. All these options ultimately increase the load capacity, but in every case there is still a limitation of the actual load bearing surface area per ball bearing. This is where the satellite roller screw has a large and legitimate advantage. As shown in the cut away photo; A satellite roller screw employs, matched rollers to rotate (or satellite as the product name suggests) around the screw during actuation instead of ball bearings. By its inherent design, there is an immediate increase in the physical amount of contact points on the screw that can support the load compared with that of the same diameter ball screw. The admissible static and dynamic load capacities are therefore considerably higher than that of a ball screw for the same diameter. In fact the static load can be 3 times greater than that of ball screws and their lifespan is 15 times longer. The many points of contact also give a satellite roller screw greater rigidity and shock tolerance than a ball screw without a compromise to friction or efficiency. Another key feature of Satellite roller screws is that they can rotate significantly faster and support much greater accelerations than ball screws as there is no recycling of the ball bearings. In fact, a roller screw mechanism can handle twice the rotational speed of a ball screw. Taking the product to another level, it is possible to supply planetary roller screws with smaller leads compared to ball screws. As the lead is a function of the pitch of the planetary roller screw, the lead can be very small (0.5mm and even less). The lead can be chosen and supplied without any geometrical changes of both the screw shaft and the nut body. In a ball screw the lead is limited by the dimension (Outside Diameter) of the bearing ball, which is a standard feature. The ABSSAC satellite screw product has two standard designs directly aimed at replacing less effective ball screw designs. There is also a full design capability of the standard satellite screw program which continues to "upgrade" linear designs around the world. Applications to date have included aerospace, medical, exploration and machine tools. For further details please contact one of our sales engineers who will be happy to answer any questions you may have. Tel : 01386 421005 sales@abssac.co.uk www.abssac.co.uk | 
01386 421 005
sales@abssac.co.uk