SFU Series High Speed and High Precision CNC Ball Screw

SFU Series High Speed and High Precision CNC Ball Screw dia. 12mm, 16mm, 20mm, 25mm, 32mm, 40mm, 50mm, 63mm, 80mm, 100mm, single lead 4mm, 5mm, 6mm, 8mm, 10mm, 20mm, custom made double lead, higher lead, high speed lead.



Model & Specifications & Dimensions

Descriptions
Ballscrews, also called a ball bearing screws, recirculating ballscrews, etc., consist of a screw spindle and a nut integrated with balls and the balls' return mechanism, return tubes or return caps. Ballscrews are the most common type of screws used in industrial machinery and precision machines. The primary function of a ballscrew is to convert rotary motion to linear motion or torque to thrust, and vice versa, with the features of high accuracy, reversibility and efficiency. JACTON provides a wide range of ballscrews to satisfy your special requirements, such as SFU, DFU, SFI, DFI, DFT, DFV, SFE, DFS, SFE, SFK, SFT, SFV series ballscrews. Can replace Taiwan HIWIN, TBI, Kuroda ballscrews, Japan THK, NSK ballscrews, Korea SBC ballscrews etc. JACTON precision ballscrews provide the most smooth and accurate movement, together with low drive torque, high stiffness and quiet motion with predictable lengthened service life. JACTON rolled ballscrews also provide smooth movement and long life for general applications with less precision in lower price. 

There are many benefits in using JACTON ballscrews, such as high efficiency and reversibility, backlash elimination, high stiffness, high lead accuracy, and many other advantages. Compared with the contact thread lead screws as shown in, a ballscrew add balls between the nut and spindle. The sliding friction of the conventional screws is thus replaced by the rolling motion of the balls. The basic characteristics and resultant benefits of JACTON ballscrews are listed in more details as follows:
1. High Efficiency and Reversibility
Ballscrews can reach an efficiency as high as 90% because of the rolling contact between the screw and the nut. Therefore, the torque requirement is approximately one third of that of conventional screws. Mechanical efficiency of ball screws are much higher than conventional lead screws. JACTON ballscrews have super surface finish in the ball tracks which reduce the contact friction between the balls and the ball tracks. Through even contact and the rolling motion of the balls in the ball tracks, a low friction force is achieved and the efficiency of the ballscrew is increased. High efficiency renders low drive torque during ballscrew motion. Hence, less drive motor power is needed in operation resulting in lower operation cost. JACTON uses a series of test equipment and testing procedures to guarantee the efficiency.
2. Quietness
High quality machine tools require low noise during fast feeding and heavy load conditions. JACTON achieves this by virtue of its return system, balltrack designs, assembly technique, and careful control of surface finish and dimensions.
3. Advantages Over Hydraulic and Pneumatic Actuators
The ballscrew used in an actuator to replace the traditional hydraulic or pneumatic actuator has many advantages, i.e. fast response, no leakage, no filtering, energy savings and good repeatability. 
4. Predictable Life Expectancy
Unlike the useful life of conventional screws which is governed by the wear on the contact surfaces, JACTON's ballscrews can usually be used till the metal fatigue. By careful attention to design, quality of materials, heat treatment and manufacture, JACTONs ballscrews have proved to be reliable and trouble free during the period of expected service life. The life achieved by any ballscrew depends upon several factors including design, quality, maintenance, and the major factor, dynamic axial load (C). Profile accuracy, material characteristics and the surface hardness are the basic factors which influence the dynamic axial load. It is recommended that the life at average axial load should be a minimum of 1x10x10x10x10x10x10 revs). High quality ballscrews are designed to conform with the B rating (i.e. 90% probability of achieving the design life). Fifty percent of the ballscrews can exceed 2 to 4 times of the design life.
5. High Lead Accuracy
For applications where high accuracy is required, JACTON modern facilities permit the achievement of ISO, JIS and DIN standards or specific customer requirements. This accuracy is guaranteed by our precise laser measurement equipment and reported to each customer.
6. Low Starting Torque and Smooth Running
Due to metal to metal contact, conventional contact thread lead screws require high starting force to overcome the starting friction. However, due to rolling ball contact, ballscrews need only a small starting force to overcome their starting friction. JACTON uses a special design factor in the balltrack (conformance factor) and manufacturing technique to achieve a true balltrack. This guarantees the required motor torque to stay in the specified torque range. JACTON has special balltrack profile tracing equipment to check each balltrack profile during the manufacturing process.
7. Backlash Elimination and High Stiffness
Computer Numerically Controlled (CNC) machine tools require ballscrews with zero axial backlash and minimal elastic deformation (high stiffness). Backlash is eliminated by our special designed Gothic arch form balltrack and preload. In order to achieve high overall stiffness and repeatable positioning in CNC machines, preloading of the ballscrews is commonly used. However, excessive preload increases friction torque in operation. This induced friction torque will generate heat and reduce the life expectancy. With our special design and fabrication process, we provide optimized ballscrews with no backlash and less heat losses for your application.

Lubrication Instructions
1. A ballscrew has to be thoroughly cleaned in white spirit and oil to protect against corrosion. Trichloroethylene is an acceptable degreasing agent, ensuring the ball track is free from dirt and damage free (Paraffin is not satisfactory). Great care must be taken to ensure that the ball track is protected from impacts caused by other components or tools, and that metallic debris does not enter the ball nut. In view of the ballscrews life and efficiency, adequate lubrication is necessary. To achieve the maximum life, the use of antifriction bearing oils is recommended. DO NOT use lubricants containing MoS2 or graphite. Normally, you can use lubricants according to the other machine components or lubricants commonly used for ball bearings. Oil mist baths or drip feeds are acceptable. However, direct application to the ball nut is recommended. A one time lubrication of a ballscrew is not sufficient.
2. The selection of lubrication will directly influence the temperature rise of the ballscrew. The basic oil viscosity requirement depends on the speed, working temperature, and the load condition of the application. A generalization is to say that when the working speed is higher and the working load is lower, using a lower viscosity oil is better. This is inversely proportional. In high speed and heavy load applications, forced cooling may be necessary.
3. Select a suitable ballscrew grade for the application. Install with the corresponding mounting disciplines. For example, precision ground ballscrews such as those used in CNC machine tools demand accurate alignment and precision bearing arrangement, where the rolled ballscrews are used for the less precision applications, such as packaging machinery which require the less precise support bearing arrangement. It is especially important to eliminate the misalignment between the bearing housing center and the ball nut center. This would result in unbalanced loads which include radial loads and moment loads. These can cause malfunction and reduce the service life.
Important Note: Unless otherwise indicated, ballscrews are shipped with anti-corrosion grease and should be lubricated prior to running the machine for the first time.

Application
1. Machine tools.
2. Factory automation equipment etc.
3. Transport machinery Material handling equipment, nuclear reactor-actuator etc.
4. Industrial machinery Printing, paper-processing, automatic machines, textiles etc.
5. Electronic machinery Robot, measuring instruments, medical equipment, X-Y table,
6. Aircraft applications: aircraft flaps, actuators, airport loading equipment etc.