Reciprocating Compressors
Body styles types
• hermetic
• semi-hermetic
• open-belt driven (pulley and flywheel)
• open direct drive (shaft coupling)
Main Parts
• crankshaft
• (crank throw – bolted)
• (eccentric – cast)
• piston
• connecting rods
• cylinder
• piston rings (1 ring, 2 rings, or oil sealed no rings)
Suction and Discharge Valves
• Reed
• Ring
• Discus
Valve plate and gasket
Cylinder head and gasket
Methods of Cooling
• Air Cooled (fins)
• Water Cooled (water jacket)
• Refrigerant Vapor cooled (travels through motor)
Hermetic : primary method of cooling Vapor/Oil
Semi-Hermetic : vapor/air/water/oil
Open Drive : oil
Lubrication methods
• splash : no oil pump (slinger)
• forced : oil pump
Capacity Control Methods
• on/ off
• speed control
• multiple compressors
• mechanical cylinder unloader (operated by pressure or electrically controlled by suction pressure), cylinder bypass, suction cut-off, hydraulic
Hot Gas Bypass
• to suction
• to evaporator inlet
* try to match the compressor capacity with actual load |
