Skip to main content

PREVENTING CREEP IN SUBMERSIBLE PUMP BEARINGS

Submersible pumps are commonly used in various industries such as construction, mining, wastewater treatment, agriculture, and general manufacturing. Typically, these pumps consist of a vertical electric drive motor that is directly connected to the impeller, and they are designed to operate for long periods with minimal maintenance.

BEARING ARRANGEMENT

The bottom bearing, also known as the locating bearing, usually consists of a double-row angular contact ball bearing or a pair of angular contact bearings, which are responsible for supporting the axial and radial loads generated by the pumped fluid. Since the bearing is subjected to heavy loads, it is important to select the appropriate bearing to achieve the desired service life. On the other hand, the top free bearing is generally a deep groove ball bearing that takes a light radial load. Typically, C3 clearance is used to compensate for the reduction in clearance caused by the heat generated by the electric motor.

CREEP PHENOMENON IN TOP BEARINGS

The lightly loaded top bearing is expected to have a long service life. However, sometimes, its life is significantly reduced due to creep. The combination of a light radial load and a loose fit in the housing can result in relative slippage between the outer ring and the housing. Creep is a phenomenon where surfaces that fit together move relative to each other, resulting in a polished bearing ring surface, which may be accompanied by scoring or wear.

COUNTERMEASURE

One popular countermeasure used by pump manufacturers is to machine an annular groove in the housing bore and insert an O-ring to prevent creep between the bearing's outer diameter and the housing.

NSK SOLUTION

NSK offers Creep-Free bearings that provide better creep prevention with their integrated double O-rings. These bearings offer submersible pump manufacturers the following advantages:

  • Excellent creep prevention.
  • Easy assembly as the Creep-Free bearings can be fitted with a loose housing bore tolerance
  • Reusable housing as very little abrasion occurs on the housing bore.
  • Cost savings as pump manufacturers do not need to machine a groove in the housing bore and insert their own O-ring.
Download NSK Pump and compressor bearings Brochure:


Hello there! If you're enjoying using our website and finding our articles helpful, we would really appreciate your support. With your help, we can continue to develop resources and provide you with even more valuable content. Thank you for your support.
Labels:

Comments

Post a Comment

Popular posts from this blog

Dry Gas Seal Failure Modes

BY BHUSHAN NIKAM. Invented in the mid-20th century and typically equipped in process gas centrifugal, dry gas screw compressors and expanders, dry gas seals (DGS) are the preferred gas lubricated dry seal solutions available on the market. They have become the standard for new machines. DGS are robust, simple, consume less power, and are more efficient in reducing leakage than their predecessor. Various configurations such as tandem with and without an intermediate labyrinth ( Figure 1 ), single ( Figure 2 ), and double ( Figure 3 ) are available & shall be selected based on process requirements. In this article, we discuss the various DGS failure modes and how they should be addressed:  PRESSURIZED HOLD/STANDBY Pressurized hold, also called settle-out condition, occurs when the compressor remains at a standstill, but the casing is pressurized. If an alternate process gas lacks sufficient pressure and flow, process gas enters the seal cavity through the process labyrinth ...
Post a Comment
[Read more...]

Understanding the Causes of Pump Shaft Breakage

By NTS. Pump shafts are essential in many industrial and commercial applications, providing the necessary mechanical force to move fluids through pipelines and process systems. However, when a pump shaft breaks, it can cause significant downtime, production losses, and safety risks. In this article, we will explore the common causes of pump shaft breakage and how to prevent it from occurring. 1. Excessive Load  The most common cause of pump shaft breakage is excessive load. When a pump is overloaded, it places a significant amount of stress on the shaft, causing it to bend, warp, or break. Overloading can be caused by a variety of factors such as a clogged discharge line, worn impeller, or damaged bearings. Proper maintenance, regular inspections, and monitoring of the pump's performance can help prevent overloading. 2. Misalignment  If the pump and motor are not properly aligned, it can cause stress on the pump shaft and lead to breakage. Misalignment can occur due ...
Post a Comment
[Read more...]

5 Important Maintenance Metrics and How To Use Them

By  Bryan Christiansen,  Limble CMMS. Source : maintworld.com Effective maintenance of equipment is a critical factor in delivering quality operations that provide timely resources at a minimal cost. However, those in the maintenance field understand that equipment reliability does not come easy.  Organizations need to set quality benchmarks to measure the current effectiveness and predict future performance and use the data obtained to understand where to make improvements.   One way to do this is by using different maintenance metrics to understand the equipment performance. These metrics are very important as they can mean the difference between achieving the overall business goals and explaining how unexpected breakdowns caused yet another production delay.   Maintenance Metrics You Should Be Measuring What are the maintenance metrics? There are two categories of maintenance key performance indicators which include the leading and lagging indicators....
Post a Comment
[Read more...]

Top 8 Reasons for Mechanical Seal Failure and How to Prevent Them

Mechanical seals are critical components of pumps, responsible for maintaining a fluid-tight seal between the rotating shaft and the stationary pump housing. However, these seals can fail due to various factors, leading to leakage, reduced pump efficiency, and costly downtime. In this article, we will discuss the top reasons for mechanical seal failure in pumps and how to prevent them. 1-Improper Seal Selection Choosing the wrong mechanical seal can cause it to fail. Consider the following factors that can contribute to seal failure: • Chemical compatibility: All seal components, such as the seal faces and O-rings, must be compatible not only with the process fluid being pumped, but also with non-process fluids used for cleaning, steam, acid, and caustic flushes, etc. • Physical degradation: Using soft seal faces on abrasive liquids will not last. Shear-sensitive liquids, like chocolate, can break down and leave behind solids (such as cocoa powder) and force out liquids (like oil). • S...
Post a Comment
[Read more...]

Technical questions with answers on gas turbines

By NTS. What is a gas turbine? A gas turbine is an engine that converts the energy from a flow of gas into mechanical energy. How does a gas turbine work? Gas turbines work on the Brayton cycle, which involves compressing air, mixing it with fuel, and igniting the mixture to create a high-temperature, high-pressure gas. This gas expands through a turbine, which generates mechanical energy that can be used to power a variety of machines and equipment. What are the different types of gas turbines? There are three main types of gas turbines: aeroderivative , industrial, and heavy-duty. Aeroderivative gas turbines are used in aviation and small-scale power generation. Industrial gas turbines are used in power generation and other industrial applications. Heavy-duty gas turbines are typically used in large power plants. What are the main components of a gas turbine? The main components of a gas turbine include the compressor, combustion chamb...
Post a Comment
[Read more...]