Nearly every industrial facility in the United States uses vertical pumps and vertical pump motors. Also known as vertical turbines or line shaft pumps, these systems are widely used in farming applications and other operations that need to move water or other liquids from lower to higher elevations.
Compared to their horizontal counterparts, vertical pump motors differ in more than their orientation. Many aspects of vertical pump motors should be understood for best utilization and maximum equipment life.
Knowledgeable supply and service partners such as HECO can help you understand the basics – including shaft type, thrust loads, and proper bearing design – all to help you select the best equipment for your application.
Shaft Types
Vertical pump motors will have a solid or hollow shaft design.
Generally, solid shaft designs connect to the pump’s shaft with a keyed coupling. This configuration is very similar to most direct-driven horizontal motors.
A hollow shaft vertical motor works a bit differently, though. The pump shaft goes inside the motor’s hollow shaft and couples at the top of the motor. These assemblies have an adjustment nut at the top that allows for simple modification of impeller depth or “lift”.
Thrust Loads
Knowing the thrust load and choosing the correct thrust bearing accordingly are two of the most important aspects when selecting an AC vertical pump motor. The thrust imparted from the pump to the motor should be obtained from the pump manufacturer.
The motor’s thrust rating comes from the thrust bearing (or bearings) in the motor’s upper bearing housing. The thrust bearing is generally an angular contact bearing, spherical roller bearing, or, on larger motors, a Hydrodynamic Thrust Bearing (tilting pad) bearing.
Non-Reversing Ratchet (NRR) Assemblies
Many times, vertical motors are equipped with a non-reverse ratchet (NRR), also known as an anti-rotation assembly. Depending on the motor manufacturer, these configurations can be designed with either ball or pin assemblies.
Ratchet assemblies have the very simple purpose of preventing the motor from spinning backward if water flow hits the impeller when the motor is off. These mechanisms prevent impellers from spinning backward and causing pump damage.
Sourcing Vertical Pump Motors
Most motor manufacturers make some form of a vertical motor.
HECO is a distributor for a variety of vertical motor manufacturers and can help you ensure that you get the correct motor for your application’s demands.
Beyond the selection, we can also partner with you to provide Predictive maintenance, Repair, and Field Service to maximize the life of your equipment and increase process uptime.
