When repairing centrifugal and axial flow pumps, axial thrust is a concern. An understanding of the causes and the mitigating provisions of various pump designs will help repair technicians to ensure those provisions work properly.

One aspect of our repair industry that seems to cause a lot of confusion is the bearing arrangements of vertical motors. There is quite an assortment of thrust bearing arrangements, and we tend to try to apply the same method for adjusting end play to all of them. That is often a bad idea, so this article will take a closer look specifically at those fitted with a spherical roller thrust bearing and repair tips unique to these designs.

Un aspecto de nuestra industria de reparación que parece causar mucha confusión es la disposición de los rodamientos de los motores verticales. Existe una gran variedad de disposiciones de rodamientos de empuje y tendemos a intentar aplicar el mismo método para ajustar el juego axial en todos ellos. Por lo general, esta es una mala idea, por lo que este artículo analizará más de cerca específicamente aquellos motores equipados con un rodamiento de empuje de rodillos esféricos y ofrecerá consejos de reparación exclusivos para estos diseños.

En este artículo discutiremos algunas de las características y propiedades clave de los aceites y grasas lubricantes.

This webinar recording reviews electric motor bearing grease and oil lubrication frequency and quantity, as well as procedures.

En toda reparación mecánica, la capacidad para desmontar, reparar y volver a montar el motor de forma apropiada sin dañar innecesariamente ninguna de sus piezas es fundamental.

Esta obra contiene muchas sugerencias sobre el manejo apropiado de las diferentes partes de un motor para minimizar los daños durante el proceso de reparación. Sin embargo, es imposible desarrollar un listado que las incluya todas.

En cambio, el principio básico de tomarse el tiempo para usar la herramienta adecuada y por lo general el procedimiento apropiado guiará a los técnicos por el camino correcto.

El propósito de este artículo es proporcionar suficientes fundamentos de rodamientos para que aquellos que son responsables de la aplicación, operación, mantenimiento y reparación de motores eléctricos puedan tomar las medidas necesarias para minimizar las fallas prematuras de los rodamientos y mejorar la posibilidad de que los rodamientos duren hasta el " "final de la vida útil", que normalmente se denomina vida útil del rodamiento L10.

The purpose of this article is to provide enough rolling element bearing fundamentals so those who are responsible for the application, operation, maintenance and repair of electric motors can take the necessary steps to minimize premature bearing failures and enhance the possibility of bearings lasting until the "end of life" predictions, which is normally referred to as L10 bearing life.

This 94-page handbook (3.5" x 6", 9cm x 15cm) contains carefully selected materials designed to assist repair firms in their everyday work. Just as important, your customers and potential customers can use this pocket handbook as a handy reference for mechanical data for motors and driven equipment.

There are times when an application calls for a motor to carry a radial load for which sleeve bearings are not suitable. In cases such as low rpm, unusual frames, etc., it may be desirable to convert a customer's existing sleeve bearing motor rather than obtaining a ball/roller replacement motor. This article contains suggested procedures as well as cautions about potential problems with such conversions.

Existen ocasiones en las que una aplicación requiere que un motor soporte una carga radial para la que los cojinetes de deslizamiento no son adecuados. En casos como bajas revoluciones, carcasas inusuales, etc., puede ser conveniente convertir el motor del cliente montado sobre cojinetes de deslizamiento envés de obtener un motor de repuesto con rodamientos de bolas / rodillos. Este artículo contiene procedimientos sugeridos y advertencias sobre problemas potenciales relacionados con dichas conversiones.

Vertical motors differ from horizontal motors in numerous ways, yet some view them as “just a horizontal motor turned on end.” The obvious differences are the (usually) thrust bearings, with arrangements varying from single- to three-thrust bearings with different orientations suited for specific load, rpm and applications. Less obvious differences are in the ventilation arrangements, shaft stiffness, degrees of protection and runout tolerances. This recording will cover those topics.

This manual covers horizontal and vertical squirrel-cage induction motors in the 300 to 5,000 horsepower range, low- and medium-voltage. Most of the principles covered apply to other sizes as well. This manual focuses primarily on IEC motors and standards.

This webinar recording focuses on:

• Motor assembly issues
• Electrical and mechanical inspection
• Static and run testing
• AC motors with ball, roller and sleeve bearings

My first exposure to synthetic lubricants for rolling element bearings was during repair of high-speed, automotive engine-test dynamometers. For several years, our service center had repaired similar machines with rolling element bearings, but they were all oil lubricated by pump systems with specially-selected fittings near the bearings to deliver only small amounts of oil per minute.

We began to see rolling-element-bearing machines in for repair that were grease lubricated, and these displayed a specific make and type of lubricant on the nameplate. We purchased what was specified on the nameplate and all was well. Over time, we began to see more machines specifying the same make of grease, but a different grade or type. This led me to begin looking into the differences in the products.

Mi primera experiencia con lubricantes sintéticos para rodamientos con elementos rodantes fue durante la reparación de dinamómetros para probar motores de automóviles de alta velocidad. Durante varios años nuestro centro de servicio había reparado máquinas similares con rodamientos con elementos rodantes, pero todas ellas estaban lubricadas con sistemas de bombeo de aceite con accesorios especiales cerca de los rodamientos para suministrar solo pequeñas cantidades de aceite por minuto.

Comenzamos a ver máquinas enviadas para reparación con rodamientos con elementos rodantes lubricadas con grasa y estas indicaban en la placa de datos una marca y tipo de lubricante específicos. Compramos lo que estaba especificado en la placa y todo salió bien. Con el tiempo, comenzamos a ver más máquinas que especificaban la misma marca de grasa, pero con un tipo o grado diferente y esto me condujo a comenzar a buscar las diferencias en los productos, ya que uno era muy costoso y tenía una vida útil limitada.

Many of your customers have good in-house predictive maintenance departments and others outsource that skill. Either way, they should know when a bearing is deteriorating and remove the motor from service before it turns into a catastrophic failure. That saves a lot of maintenance dollars, which is great. But if the customer stops there, without discovering why that bearing is bad, your repaired motor could be returned with the same problem again. Defective bearings often hold a great deal of evidence, if we only look for it. The key is communication with the customer so that we repairers know that the motor was removed for bearing faults, and so that we can go a step further in the diagnostic process. Especially with the prevalence of variable frequency drives (VFDs), bearing currents cause a significant number of bearing failures. If you know the motor is operating from a drive, there are corrective measures to prevent future failures of the same type. And those extra steps are billable extras. Neglecting these additional inspection steps is like leaving money on the table, for both the service center and the customer.

Muchos de sus clientes cuentan con buenos departamentos de mantenimiento predictivo propios y otros lo subcontratan con proveedores externos calificados. En ambos casos, ellos deben saber cuando un rodamiento presenta deterioro y sacar de servicio el motor antes que el fallo se vuelva desastroso. Los rodamientos defectuosos aportan una gran cantidad de evidencias, si solamente las buscamos.

End users frequently demand that EASA service centers provide an array of test data at the conclusion of the service/repair process. These tests are normally to validate compliance with the customer’s motor repair specifications. One of the more common tests involves running the motor no-load and providing the motor owner with electrical test information and vibration spectrums covering various frequency bands.

Ball and sleeve bearing motors can always be test run without any type of external load on the motor and bearings. However, when repairing a motor equipped with roller bearings that is used in an application with a radial load, such as a belted load, it is not advisable to perform the standard no-load test run for any length of time. Yet the no-load test run is a crucial step in the repair process to ensure proper operation. Without that radial load, the bearings can be damaged. This article will describe two ways to put a load on the shaft of a motor and therefore the roller bearing, so that it can be test run to ensure that it has been properly repaired.

Much of what is discussed in this article applies to all rolling bearings, both ball and roller. Our focus, though, will be on issues that relate mostly to ball bearings used in electric motors. The intent is to address some of the fundamentals of rolling bearing enclosures, internal clearances and fits. We deal with rolling bearings every day, but we don't always consider some of these fundamentals until there is a bearing-related problem.