Understanding Hermetically Sealed Compressors

The question asks about a specific type of compressor system where the compressor and its driving motor are integrated into a single, sealed unit. This configuration offers several advantages, primarily preventing refrigerant leakage and contamination from the external environment.

What is a Hermetically Sealed Compressor?

A hermetically sealed compressor is a design where the electric motor that drives the compressor is located within the same welded or brazed steel casing as the compressor itself. The motor and compressor share a common shaft. The entire unit is sealed, meaning there are no shaft seals that could leak refrigerant or allow moisture and contaminants into the system.

• The motor and compressor operate on the same shaft.
• They are enclosed together in a single, sealed casing.
• This design eliminates the need for a shaft seal, which is a common point of leakage in other compressor types.
• The refrigerant flows around the motor, helping to cool it.

This integrated design is common in many refrigeration and air conditioning systems, particularly in smaller to medium-sized units like household refrigerators, freezers, and window air conditioners.

Comparing with Other Compressor Types

Let's briefly look at why other options don't fit the description:

• Screw compressor: This refers to the mechanism of compression using rotating screws. While screw compressors can be hermetic, semi-hermetic, or open-drive, the term "screw compressor" alone doesn't define the sealed, integrated motor/compressor unit described.
• Reciprocally sealed compressor: The term "reciprocally sealed" is not a standard classification. Reciprocating compressors use pistons, and they can also be open, semi-hermetic, or hermetic depending on how the motor is connected and enclosed.
• Centrifugal compressor: This refers to the compression mechanism using centrifugal force (like a fan or impeller). Centrifugal compressors are typically used in larger systems and can also be open, semi-hermetic, or hermetic. The term itself describes the compression method, not the motor/casing configuration.

Therefore, the description provided, where the compressor and motor are on the same shaft and enclosed in a common casing, specifically defines a hermetically sealed compressor.