What Are The Disadvantages of Not Straightening The Screw Rod?

If the screw rod(such as a ball screw) is not straightened (or is bent and deformed), it will have serious negative impacts on the performance, lifespan and safety of the mechanical equipment, mainly manifested in the following five aspects:

1. The positioning accuracy and processing quality will significantly deteriorate

1.1. Positioning deviation and poor repeatability:

The bending of the screw rod will cause the nut to have axial wobbling and displacement deviation when moving, resulting in the straightness of the machine tool worktable or automated equipment exceeding the standard, causing the processed workpiece to have unstable dimensions and excessive form and position tolerances.

1.2. Reverse clearance increases:

The bending deformation will aggravate the wear of the screw rod and the nut, causing the transmission clearance to increase, further deteriorating the positioning accuracy.

2. The running resistance increases sharply and the motor overloads

2.1. Friction torque increases dramatically:

The bending or misalignment of the screw rod will cause the balls to lean towards one side in the raceway, resulting in a sharp increase in local contact stress, and the running resistance will increase exponentially.

2.2. Motor overload and alarm:

To overcome the additional friction resistance, the servo motor must output a larger torque, which is likely to trigger servo system alarms, motor overheating, and even motor burnout.

3. Abnormal vibration and noise

Vibration and abnormal sounds:

The eccentricity during operation will cause uneven force on the balls, triggering continuous abnormal vibration and "buzzing" resonance sounds. This vibration will spread to the supporting bearings and the connection part of the motor, causing the bearing clearance to increase and the seal to be damaged.

4. Abnormal heating and thermal deformation

4.1. Local severe heating:

Excessive local contact stress and intensified friction will cause a large amount of heat to be generated at the screw rod and nut part, resulting in axial thermal expansion of the screw rod after temperature rise.

4.2.Negative Cycle:

Thermal deformation will further damage the originally fragile coaxiality， forming a "the hotter， the more off-center， the more hot" vicious cycle， exacerbating component deformation.

5. Component accelerated wear and early failure (fatal damage)

5.1. Local wear and peeling：

Uneven force will accelerate local wear， causing rapid fatigue peeling on the raceway surface， shortening the service life of the screw rod.

5.2. Ball jamming and fragmentation：

Severe bending will cause damage to the return pipe or reverse device inside the nut. The ball's path in the circulation channel is blocked， and in severe cases， it will cause the ball to jam， resulting in an instantaneous interruption of the transmission； long-term alternating impact loads and local stress concentration will also cause the ball to fracture， and the screw rod to suffer early fatigue fracture， causing serious machine faults and production accidents.

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