The Ball screw BNT (บอลสกรู BNT, which is the term in Thai) arrangement is a power transmission linear actuator that uses rolling ball bearings to convert torque to thrust at an efficiency of more than 90%. Compared to lead screws that use a sliding mechanism, this is amazing. Linear power can be converted from angular power (a product of torque and angular velocity) to move the ball nut and any member attached. Fewer resources are required, there is less wear, the load capacity and accuracy last longer, and the lifespan is predicted with greater accuracy. Unfortunately, those benefits are at risk if the end-fixity conditions are not considered.
The linear motion of a screw is limited since it is powered by an electric motor. It is placed on bearings that share the motor’s mounting surface. An axial push at the load-carrying end (or ends) of the screw counteracts the load and acceleration acting on the ball nut. As a result, the load-bearing capacity, rigidity, speed of response, and speed of the system are all significantly affected by the screw mounting method.
Consistency And Column Strength
Column strength refers to a ball screw’s resistance to crumpling under a compressive load. The torque applied to the ball nut by the machine causes an axial load, borne by the screw. For long columns, the material strength is typically much greater than the column strength, making the column strength the determining design parameter.
Given the significance of the length-to-diameter ratio in column buckling, it makes sense that the compressive load resilience of Ball screw BNT varies with screw length. If the ratio of length to diameter (L/D) is higher than 100:1, then special design consideration is needed; regardless of the loads or the permanence, you should contact the manufacturer.
A ball screw with both ends fixed can be 112 times longer than a ball screw with both ends supported and 212 times as long as a ball screw with a free section to bear the same amount of force without buckling. These vast variations necessitate that information for all four varieties of end fixity be part of the manufacturer’s charts.
The Rapidity At The Critical Point
Nowadays, machinery needs faster actuation and shorter cycle times to increase output. Choosing the proper ball screw can aid in achieving fast cycle times, as these typically go hand in hand with the requirement for high-duty repetitions and extended travel life.