How to Align an Expanding Sleeve

When aligning an expanding sleeve coupling (such as between a motor and a compressor), a common method is to measure the axial and radial misalignment using a set of four points on a coupling’s end face. Here’s a detailed step-by-step guide to the process:

Step 1: Select Four Measuring Points

Begin by selecting four points on the coupling’s end face: points a, b, c, and d. Points a and b represent the top and bottom points, while points c and d are for the left and right sides.

Step 2: Measure Axial Misalignment

• At the top and bottom (points a and b): Mount a dial indicator at point a and set it to zero. Then, measure the axial displacement (misalignment) at point b by checking the difference in readings.
• At the left and right (points c and d): Next, mount a second dial indicator at point c and set it to zero. Measure the displacement at point d for the radial misalignment.

These readings help determine both axial and radial deviations from alignment.

Step 3: Correct Axial Misalignment

• First, address the axial misalignment between points a and b (top and bottom). If the displacement at these points is within the acceptable tolerance range, there’s no need to adjust the motor height.
• If needed, adjust the motor’s position along the axis to ensure the top and bottom measurements are within the specified limits. Once the vertical alignment (axial direction) is accurate, proceed to address the radial misalignment.

Step 4: Correct Radial Misalignment

• Once the axial alignment is within acceptable tolerances, focus on the radial misalignment between points c and d (left and right). Use the appropriate adjustments to eliminate or minimize the radial deviation. This may involve adjusting bolts, shifting positions, or using shims to fine-tune the alignment.

Step 5: Ensure Final Precision After Tightening

• After making the necessary adjustments for axial and radial misalignment, tighten the mounting bolts securely. Make sure the final dimensions are within the specified tolerance ranges.
• If necessary, use shims to compensate for any residual vertical misalignment, ensuring that all parts are within the required tolerance once the bolts are tightened.

By following this method, the expanding sleeve coupling will be aligned precisely, which helps prevent operational issues caused by misalignment, ensuring smoother performance and extended service life for the equipment.