components and seal the compressor a clamp engages the forward and the rearward housing portions and is rotated to compress the two together it maintains a desired clamping force under various operating and environmental conditions application_number US 12068802 A description fig1 5 illustrate a first embodiment of an air conditioning compressor housing assembly 20 in accordance with the present invention the housing assembly 20 is designed to form a portion of a piston type refrigerant compressor the pistons drive mechanism and other components are not illustrated herein but are conventional in nature and are well know to those skilled in the art of refrigerant compressors for automotive vehicles for example the other components may be similar to those of a swash plate refrigerant compressor as disclosed in u s pat no 6 318 972 incorporated herein by reference while the example in the preferred embodiment illustrates a compressor housing for a swash plate type of compressor the present invention is also applicable to other types of refrigerant compressors as well the housing assembly 20 includes a front housing portion 22 also sometimes called a crankcase a rear housing portion 21 also sometimes called a cylinder head a cylinder block 23 a valve plate assembly 27 and a ring clamp 31 when referring to front and rear herein the wording is merely used for convenience in describing the assembly and the orientation of the parts relative to one another but does not imply any particular orientation of the assembly within a vehicle the front housing portion 22 rear housing portion 21 and the ring clamp 31 are preferably made of aluminum although they may be made of other materials preferably these three components are all formed.