1.What is the ball screw?

Ball screw is the ideal product to convert rotary motion into linear motion or to convert linear motion into rotary motion.

The ball screw is composed of a screw, a nut, a steel ball, a pre-compression piece, an inverter, and a dustproof device. Its function is to transform the rotary motion into a linear motion. This is the further extension and development of the Acme screw. The significance of this development is to change the bearing from a sliding motion to a rolling motion. Ball screws are widely used in a variety of industrial equipment and precision instruments due to their low frictional resistance.

Ball screw is the most commonly used transmission component in machine tools and precision machinery. Its main function is to convert rotary motion into linear motion, or to convert torque into axial repetitive force, with high precision, reversibility and high. The characteristics of efficiency.

Since the development of ball screws, it has been widely used in the positioning precision control of various industrial machines, such as precision machine tools, industrial machinery, electronic machinery, and transport machinery. 

2.What is the use of ball screws?

Ultra high DN ball screw: high speed machine tool, high speed integrated machining center machine.

End cap ball screw: fast handling system, general industrial machinery, automated machinery.

High-speed ball screw: CNC machinery, precision machine tools, industrial machinery, electronic machinery, high-speed machinery.

Precision grinding grade ball screw: CNC machinery, precision machine tools, industrial machinery, electronic machinery, conveying machinery, aerospace industry, actuators and valve switching devices used in other antennas.

Nut Rotary (R1) series ball screw: semiconductor machinery, industrial robots, woodworking machines, laser processing machines, conveyors, etc.

Rolling grade ball screw: low friction, smooth running, and fast delivery and low price.

Heavy duty ball screw: all-electric injection molding machine, punching machine, semiconductor manufacturing equipment, heavy duty brake, industrial machinery, forging machinery.

3.What types?

There are two common types of circulation: outer loop and inner loop. The ball is sometimes out of contact with the lead screw during the cycle, called the outer loop; the inner loop is always in contact with the lead screw.

1) External circulation: The outer circulation is that the ball re-enters the circulation between the screw nut through the spiral groove on the outer surface of the nut or the cannula after the end of the circulation process. The outer circulation ball screw nut pair mainly has end cap type, cannula type and spiral groove type according to the return mode of the ball circulation.

Commonly used external circulation type end cap type; intubation type; spiral groove type.

In the end cover type, a longitudinal hole is machined on the nut as a return passage of the ball, and a return port of the ball is opened on the cover plate at both ends of the nut, and the ball enters the return pipe to form a circulation. Intubation type, which uses a curved pipe as a return pipe, this structure is technically good, but the radial size is large because the pipe protrudes outside the nut.

Spiral groove type, which is a spiral groove milled on the outer circumference of the nut. The through hole is drilled at both ends of the groove and is tangent to the thread raceway to form a return passage. This structure is smaller than the radial dimension of the cannula structure, but Manufacturing is more complicated. The outer circulation ball screw outer circulation structure and manufacturing process are simple and widely used. The disadvantage is that the raceway joints are difficult to smooth and affect the smoothness of the ball raceways.

2) Inner loop: The inner loop uses an inverter to realize the ball cycle. There are two types of reverser.

The cylindrical male key reverser has a cylindrical portion embedded in the nut and a reverse groove at the end. The reverse groove is positioned by the outer circular surface of the cylinder and the round key at its upper end to ensure alignment of the thread raceway. The flat insert invertor, the reverser is a generally round flat key insert, the insert is embedded in the slot of the nut, and the end is provided with a reverse groove, which is positioned by the outer contour of the insert.

Compared to the two types of inverters, the latter is smaller in size, thereby reducing the radial dimension of the nut and shortening the axial dimension. However, the outer contour of the reverser and the slot size accuracy on the nut are required to be high.

The nut of the ball screw can be divided into a curved pipe type, a circulator type, and an end cover type according to the circulation mode of the steel ball. The characteristics of these three cycles.

Curved tube type (SBN, BNF, BNT, BNFN, BIF and BTK types): These models are searchable.

Circulating guide type (HBN type): These models are the most typical nuts, which are used to circulate steel balls by using curved tubes. The steel ball is drawn from the groove of the screw shaft into the elbow, and then returned to the groove for infinite cyclic motion.

Circulator type (DK, DKN, DIK, JPF and DIR types): These models are the smallest type of nut. The circulator changes the direction of travel of the steel ball and returns to the original position beyond the outer diameter of the screw shaft for infinite cyclic motion.

End cap type (SBK, SDA, SBKH, WHF, BLK, WGF, BLW, WTF, CNF and BLR types)

These models are the most suitable nuts for high speed feed. The steel ball is drawn into the through hole of the nut from the groove of the screw shaft by the end cover, and returns to the groove through the through hole to perform an infinite circular motion.

(1) Never remove the ball screw. Otherwise, it is easy to cause the entry of dust, which causes the accuracy to drop or cause a malfunction.

(2) Since the ball assembly loses its function due to assembly errors due to reassembly, it is hoped that users will not reassemble. If the product is returned to the company, it can be repaired and reassembled in a paid form.

(3) The ball screw shaft or nut may fall off due to its own weight. Please be careful not to get hurt. Inadvertently, the function of the product may be lost due to the bump of the track or the damage of the circulating parts. At this time, it is necessary for the company to inspect it, so be sure to return the dropped product to the company, and the company will be responsible for the inspection in a paid form.

(4) If there are signs such as damage or damage to the circulating parts, the outer diameter of the shaft, the track, etc., the circulation will be poor, resulting in loss of function of the product.

The ball screw pair can be used with lubricants to improve wear resistance and transmission efficiency. Lubricants are divided into two major categories of lubricants and greases. Oil for lubricating oil, turbine oil No. 90~180 or spindle oil No. 140. Grease can be used as a grease. Grease is added to the housing space of the threaded raceway and the mounting nut, and the lubricating oil is injected into the nut space through the oil hole in the housing.

Ball screw pairs and other rolling friction transmission components can be considered to work almost without wear as long as abrasive particles and chemically active substances are avoided. However, if dirt falls on the raceway or dirty oil is used, it will not only hinder the normal operation of the ball, but also cause a sharp increase in wear.