The choice of an off the shelf or a custom designed and manufactured ball screw assembly is largely a factor of the specific requirements for the component. Off the shelf or standard sizes and options are going to be less costly, but they are not always the correct option for the equipment or system.
Whenever a custom ball screw and ball nut assembly is required, shopping around for a reliable service to engineer, design and produce the ideal part is important. This means ensuring the ball nut and the ball screw is precision machined and crafted to the specific requirements to ensure smooth action and flawless movement up and down the screw.
The Importance of Precision Machining
The purpose of the ball screw assembly is to transfer or convert rotary motion, or the turning of the nut on the screw, to linear motion. It is also possible to have these assemblies complete the reverse action.
The ball nut and the ball screw, unlike in traditional types of systems, do not actually make contact. Instead, the nut moves along the screw through the use of balls which roll within the precision machined grooves. The balls are contained in the nut and circulate through either on the interior or the exterior.
Precision crafting of the ball screw assembly, which includes the screw and the nut, is critical for the reduction of friction as well as the maximum conversion of motion. With any irregularities in the grooves or in the design, the ball screw assembly is less efficient and will have a shorter life cycle, which results in an increase in both cost and downtime for the equipment.
In addition to precision machining, carefully designing the ball screw assembly based on the ratio of the number of threads in the nut and the screw will have a direct impact on the life cycle of the nut, which will wear faster than the screw.