Can a spindle motor carry weight?

A spindle motor is designed to rotate a workpiece or tool, and is not typically used to carry weight. However, it may be possible to use a spindle motor to support a small amount of weight if the motor is properly supported and the weight is within the mo

Spindle motors are typically used to drive spindles in machine tools such as lathes, drilling machines, and other applications that require rotary motion. They are compact motors that provide high torque output. However, due to their design and construction, spindle motors may not be well suited to carry loads or weight. Let's look at some of the factors that determine whether a spindle motor can carry weight.

Mechanical load capacity

The key factor in determining the load capacity of a spindle motor is its mechanical load capacity. Spindle motors are designed primarily for rotary motion, not for carrying axial loads. Their shafts are usually unsupported at the free end and are therefore prone to deflection under axial loads. Roller and ball bearings in spindle motors have a limited load carrying capacity. Excessive axial thrust loads can lead to wear and breakthrough, which can damage the bearings. This leads to increased friction, higher operating temperatures, and shorter bearing life.

Torque and thrust load ratings

The thrust load a spindle motor can carry is usually indirectly related to its torque rating. Higher torque motors with larger diameter shafts and bearings may have a higher thrust load capacity. However, sustained axial loads can still subject bearings to high stresses, which can lead to deformation or failure over time.

Shaft deflection under load

Axial loads applied to the spindle motor shaft can cause significant deflection. As the load increases, the unsupported shaft experiences more flexing. Excessive shaft deflection can lead to misalignment and instability, which can damage the bearings.

Effect of speed and load on motor life

Lower shaft speeds and higher axial loads tend to shorten the life of the spindle motor. The situation is further complicated by the fact that the motor draws more current during this period. Overheating, wear, and high current operation all contribute to a shorter spindle motor life. At a given speed, motor life decreases exponentially as the axial load increases.


In response to the load demands placed on spindle motors by a small number of customers, Lunyee designed and manufactured spindle motors with roller bearings to carry heavier axial loads. However, there are inherent limitations in the design of spindle motors that restrict their ability to reliably carry significant axial loads, and they are not ideal for applications requiring weight transportation.

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