What is motor pump alignment? (and why it's important to train your employees on it)

Proper motor pump alignment helps ensure your equipment has longer life spans while requiring fewer repairs and costly downtime. Here we’ll explain what motor/pump alignment is, why it’s so important, and why your maintenance staff need alignment training.

What is Motor Pump Alignment?

A motor/pump combination requires the shafts of both pieces of equipment join at a coupling point. The two shaft centerlines must be aligned so they rotate on a common, or collinear, axis.

Benefits of Motor Pump Alignment

Maintaining motor pump alignment offers multiple benefits, including:

• Minimizing the force on the seals and bearings of both machines,
• Reducing coupling wear,
• Lower energy costs,
• Increased life cycle of motor and pump components,
• Less downtime for repairs,
• Reduced parts expenses,
• Reduced inventory parts requirements.

Consequences of Misaligned Motor / Pump Shafts

Misalignment of motor/pump shafts increases the rate of wear and tear on your equipment, while increasing the amount of energy the motor/pump system consumes by up to fifteen percent. In addition, misalignment increases the risk of a number of mechanical issues, including:

• Coupling overheating and extreme wear,
• Dry element coupling fatigue,
• Pump and driver shaft failure,
• Pump and driver bearing overload,
• Damaging machinery vibrations.

Repairs related to misaligned motor/pump shafts result in system downtime and a corresponding loss of productivity. Proper maintenance by staff trained in hydraulic troubleshooting helps keep motor/pump shaft’s aligned, reducing the risk of costly repairs.

When to Align Motor/Pump Shafts?

Aligning motor/pump shafts is not a “fix it and forget it” task. Alignment is required:

• During initial pump / motor installation,
• After servicing motors and pumps,
• Whenever operating temperatures change,
• As part of scheduled preventative maintenance.

Aligning shafts during installation is a multi-step process, with alignment checked before the baseplate is grouted, after grouting, after connecting piping, and after the equipment’s first run.

How to Align Motor/Pump Shafts

When aligning motor/pump shafts it’s important to think in three dimensions. Shaft misalignment may be expressed in terms of offset (the two shafts do not match together but are still parallelly aligned) and angularity (the shafts meet at different angles at the coupling site). This creates four types of misalignment:

• Horizontal offset,
• Horizontal angularity,
• Vertical offset,
• Vertical angularity.

In most cases, the pump is permanently or semi-permanently installed, while the motor is the movable machine. Alignment, therefore, requires moving the motor in relation to the pump shaft.

The motor may be aligned vertically by shimming the motor feet. To align the motor horizontally, tools such as jacking bolts, pry bars, and hammers are required.

Motor/Pump Alignment Tools

Before physically aligning motor/pump shafts, the amount of offset and angularity needs calculating. Three alignment calculation methods are most often used:

• Straight Edge and Feeler Gauges: Used mostly for smaller motor / pump setups or in environments too cramped for other alignment methods, straight edge and feeler gauges rely on estimated shim changes, achieving alignment through the process of trial and error. One of the least expensive but least accurate alignment methods.

• Indicator Dial Indicators: A single dial indicator is laid on the pump shaft to read the level of the motor shaft, allowing maintenance crews to calculate shim changes to motor feet height. In the more complex reverse indicator method a dial indicator also reads from the motor shaft to the pump shaft. Mathematical formulas are then used to calculate alignment changes.

• Laser-optic Devices: By far the most accurate way to calculate motor/pump alignment, pulsating laser devices determine shaft positions, relaying the information to a microprocessor that calculates needed alignment changes. While expensive, laser-optic devices offer a degree of accuracy that other alignment tools lack and are easily mastered by employees after short periods of training.

Why Your Employees Should be Trained on Motor/Pump Alignment

Cost savings are the primary reason to train employees in pump maintenance. A well-maintained motor/pump combination has a longer lifecycle and fewer failures than unmaintained systems. Fewer system repairs mean less downtime and fewer interruptions in production. Motor/pump alignment issues are responsible for many pump-related issues—issues you can avoid with a few days of training.

Learn more about our pump maintenance and repair course today!