What Is Vacuum Pressure Impregnation?
For many types of rotors, stators, transformers, capacitors, and other electric motor components, VPI adds critical protection from breakdowns and degradation due to harsh operating conditions. This multistep process completely coats and encloses components, filling empty spaces between windings and insulation. The result is a bonded and impervious solid mass.
The VPI process begins with preheating the component, followed by dry vacuuming in a pressure vessel to pull out any air in the component. Next is wet vacuum, in which the resin or varnish is introduced to the impregnation chamber while still under vacuum. The vacuum is released and over pressure is applied forcing the resin or varnish deep into the voids and open spaces in the component. Finally, the excess resin or varnish is returned to a reservoir, and the coated part is cured in a special oven.
How VPI Protects Electric Motor Components
VPI is a highly effective way to make electric motors perform better and last longer. Some of the protective qualities VPI imparts include:
- Closes air gaps that can let in corrosive moisture or chemicals.
- Reduces physical stress and damage from vibrations due to start/stop cycles.
- Improves heat dissipation, which helps prevent overheating or breakdowns.
- Increases mechanical strength and abrasion resistance.
- Extends motor useful life and reliability.
As a result of these advantages, VPI equipment is a critical aspect of manufacturing for many types of equipment, including:
- High-voltage motors.
- Locomotive drive motors.
- Large industrial equipment motors.
- Large-scale lifting magnets.
- Power Transmission.
At Godfrey & Wing, through our Imprex Division, we design reliable and efficient vacuum pressure impregnation systems that integrate into manufacturers’ facilities for efficient VPI processes.
VPI System Components
At Imprex, our vacuum pressure impregnation systems include the following components:
- Vacuum + Pressure Vessel Assembly.
- Vacuum Pump Assembly.
- Reservoir.
- Reservoir Cooling and/or Heated Capability.
- Resin Transfer Piping.
- Programmable Logic Controller (PLC) for Automation.
Additional VPI Options
To help meet our customers’ manufacturing processes and diversity of components, Imprex vacuum pressure impregnation equipment can be customized with additional features such as:
- Chamber Liner.
- Filter for Transfer Line.
- Data Logging.
- Temperature Monitoring Capability.
