Search Results

Various physical conditions of the friction surfaces were studied to increase the breakaway torque of the electromagnetic clutch for the automotive air conditioning compressor. The conventional ground steel-ground-steel combination had a disadvantage of low breakaway torque in the running-in period of engagement cycles. This situation was greatly improved by using the combination of the ground armature plate and the machined rotor with zinc plating. In this new technique, the pitch and depth of the machining mark relative to the plating thickness was found to be important. Combinations of machined armature plates and the machined rotors, with or without zinc plating, were also promising, and the mechanism of friction with these surface combinations were analyzed.

Mobile Air Conditioning Compressors with the scroll mechanism design are superior in noise, vibration and harshness (NVH) levels, and in efficiency. For further NVH improvements; for improved comfortability; to enhance the manufacturability to meet the increasing market volumes; and to give better vehicle compatibility in weight reduction and increased durability, the New Type TR Compressor is presented.

Certain important factors must be considered when the current refrigerant for automotive air conditioning systems, (A/C), is changed from CFC12 to the ozone safe HFC134a. This paper will focus on lubricant compatibility by presenting a screening process which will cover: a screening table of essential physical properties general information on types of available lubricants tests of chemical stability lubricity compatibility with elastomers methods for testing compressor durability service engineering

Several field problems are anticipated with HFC-134a systems. To be evaluated and clarified are the impacts upon: compressors and systems of chlorine based solvents left in the system from flushing or parts cleaning; mixing in CFC-12; mixing the new lubricants with mineral oil; the effects of certain lubricants and HFC-134a's high hygroscopicity and others. The whole industry should share information and endeavor to maintain the reliability of the new systems from a service engineering standpoint. STARTING IN 1991 the ozone safe HFC-134a refrigerant is expected to replace the conventional CFC-12 in car air conditioning systems and in model years 1994-1995 the major portion of the market will be the new systems. The components/elements and parts used in the new air conditioning systems will embody different designs with new materials which are now considered to be compatible with the new refrigerant-lubricant mixtures.

Scroll wall strength is of critical importance to compressor reliability and durability. This is most critical at the center portion of the scroll wall as it is exposed to the highest working gas pressure in the A/C system as well as to high discharge gas temperatures. This paper will focus on a method to achieve stress reduction at the center portion of the scroll wall by using Finite Element Methods (FEM) analysis. Scroll wall endurance was evaluated utilizing an accelerated durability test which covered the following: Optimization method of scroll wall center portion geometry. Effect of stress reduction by optimization of fillet radius. Impact of discharge gas temperature on scroll wall endurance.