Ball screws with nut cooling
Second Quarter 2022
Editor's Choice
Shaft power components
Machining centres feature ball screws with nut cooling to increase surface quality of milled parts. NSK ball screws with nut cooling are setting new standards in the precision of machine tools with mechanical drive components. Confirmation comes not only from NSK’s own testing, but from machine tests conducted with Chiron Group, a well-known manufacturer of machining centres. NSK ball screws contribute to the outstanding surface quality of milled parts produced by Chiron Group’s new CNC machining centres.
The machine tool industry uses ball screws to convert the rotary motion of an electric motor into linear motion. Very often, the positioning accuracy, as well as the travel speed and acceleration, have to endure extreme demands. As a result of axial forces, acceleration and speed, the ball screw generates frictional heat. This heat can cause the length of the screw to increase due to thermal expansion and hence lead to very slight but often critical positioning inaccuracies that may impair machining quality. To help avert this outcome, many machining centres are equipped with a length scale that measures the actual position of the tool, while for those that require higher positioning accuracy it is possible to use ball screws with hollow shafts. In the latter, coolant passes through the shaft to remove heat from the system. This method is quite costly, however, because rotating screws require a rotary union in addition to the hollow bore.
A new approach is to cool the nut, which means there is no need for an expensive hollow bore and rotary union as cooling takes place directly at the point where the heat is generated. Another key benefit is that the heat generated in the ball screw no longer dissipates directly in the machine. This thermal decoupling between the machine and ball screw is important because any heat can impair dimensional stability. The results now prove that by cooling the nut, it is possible to increase the surface quality of machined components.
NSK engineers designed the nut body so that the changes to the ball screw caused by cooling have no negative influence on its performance profile, as confirmed by endurance tests at NSK’s Technology Centre. Many years of cooperation with Chiron Group have also confirmed these results in practice. The use of NSK ball screws with cooled nuts means that machining centres of the PR 16 and 22 Series operate with exceptionally high precision, which not only applies to ease of positioning, but also to machining accuracy and surface quality.
In two specific Chiron series, the ball screws are also equipped with NSK’s highly effective X1 seal, which protects the nut from contamination and retains lubricant within the nut for an extended period. Looking ahead, NSK intends to pursue its collaboration with the Chiron Group and thus continue optimising precisely targeted cooling technology for ball screws. This teamwork will enable developers to deepen their knowledge of ball screws and how they influence machine performance.
The Chiron Group, headquartered in Tuttlingen, is a global company specialising in CNC vertical milling and mill-turn machining centres, as well as turnkey manufacturing solutions. The group has a global presence, with production and development sites, sales and service subsidiaries and sales agencies worldwide. Around two thirds of machines and solutions that are sold are exported. Key customer sectors are the automotive, mechanical engineering, medicine and precision engineering, aerospace industries and tool production.
Further reading:
Planar motor system for quality assurance
Beckhoff Automation
Editor's Choice Electrical switching & drive systems & components
Achieving the shortest possible inspection times, even when working with different components, is paramount when it comes to series production. This is precisely what special machine builder, stoba Sondermaschinen set out to achieve with its InspectorONE optical inspection system, which is based on deep learning and features the Beckhoff XPlanar planar motor system at the conveyor system core.
Read more...
Robotic solution for adhesive tape application with flexible control
Beckhoff Automation
Editor's Choice Robotics & Mechatronics
In industry, even elaborate processes, such as the application of adhesive tape to parts with varying geometries are automated. Innovative Automation has developed a platform with Beckhoff control technology and a remote feeding module, which increases productivity and enables flexible customisation for different requirements.
Read more...
The world’s most powerful worm
Editor's Choice Electrical switching & drive systems & components
Geothermal energy from the natural heat of the Earth is an inexhaustible resource, yet the growth of the global geothermal power sector lags behind other renewable energies. Now Swiss startup, Borobotics is hoping to speed this up with its innovative new electric-powered geothermal drilling robot, which can be used to fast-track and lower the cost of heat pump installations in confined spaces.
Read more...
Problem solving under pressure
Axiom Hydraulics
Editor's Choice
The greatest strength of Axiom Hydraulics lies in the company’s ability to solve complex problems and adapt systems to meet unique challenges. This capability stems from two key factors: the diverse experience of its team members, which spans decades across multiple disciplines, and their unwavering dedication to their clients.
Read more...
New AI advisor for robot selection
igus
Editor's Choice Robotics & Mechatronics
igus’ new AI chatbot has been added to the online platform RBTX.com. The interactive consultant is designed to enable companies with little previous experience and technological expertise to quickly and reliably put together low-cost automation solutions to becoming more competitive.
Read more...
Compressed air treatment do’s and don’ts
Artic Driers International
Editor's Choice Pneumatic systems & components
As a long-established importer and manufacturer of air dryers, Artic Dryers often sees the results of poor installation and issues with aftercoolers that create serious problems in air drying systems.
Read more...
Process control system for the entire plant lifecycle
Siemens South Africa
Editor's Choice
The automation of process plants has been characterised by IT silos for a long time. The high level of IT security required was achieved through strict isolation from the outside world. However, this made unlocking the opportunities for digitalisation very difficult. This is a compelling reason to opt for Simatic PCS neo – Siemens’s completely web-based process control system with state-of-the-art IT security concepts.
Read more...
Celebrating 65 years: rebuilding and redefining its legacy
Axiom Hydraulics
Editor's Choice News & events
Founded in 1959 by Neill Simpson, Axiom Hydraulics has grown into one of South Africa’s elite hydraulic companies. Over the past six and a half decades they’ve weathered many challenges, but none as devastating as the fire of 2023.
Read more...
Monitoring the health of systems
SA Gauge
Editor's Choice Shaft power components
Pressure and temperature gauges are vital instruments in various industries. However, they are susceptible to failures that can compromise their accuracy and reliability. When these gauges fail, the consequences can be severe.
Read more...
PC-based control for advanced hydrogen storage technology
Beckhoff Automation
Editor's Choice Electrical switching & drive systems & components
The proportion of renewable energies from solar, wind and water is rising continuously. However, sufficient storage options are of the essence to use these energies as efficiently as possible. GKN Hydrogen offers a particularly compact and safe option, low-pressure metal hydride hydrogen storage systems with PC-based control from Beckhoff.
Read more...
printer friendly version