On a long line shaft, the position of the fixed bearing should be?

The correct position for a fixed bearing on a long line shaft is next to the drive coupling. This placement is crucial for several reasons. Fixed bearings provide support and stabilization for the shaft, preventing excessive movement that could lead to misalignment or failure. By positioning the fixed bearing near the drive coupling, it helps to absorb any vibrations or axial loads generated by the motor or associated equipment.

Additionally, this placement allows for compensation of thermal expansion along the shaft length since it is away from the free end of the shaft, which might experience more movement or fluctuations. The drive coupling is typically where the torque is introduced to the shaft, making it essential for the fixed bearing to be located nearby to effectively manage the stresses occurring in that area.

While a fixed bearing could theoretically be placed at the end of the shaft, at the midpoint, or near the outer race, these positions do not adequately fulfill the need for support and stabilization where the torque dynamics are most critical. The selected location also enhances overall system efficiency and prolongs the lifespan of the bearings and the shaft itself.