Abstract: A swash plate piston (20) of integral, one piece design has outer surface portions in contact with much of the total available inner surface of the cylinder bore (18), but with a basically hollow design that can be easily manufactured. Outer (36) and inner (38) semi cylindrical segments of the piston (20) extend axially back from a cylindrical head (32), but leave the center of the piston body entirely open and empty. A slanted wing member (40) extends out and down from the inner segment (38), into the outer segment (36), creating a four sided, frame like structure of superior strength. All of the outboard outer surfaces of the piston (20) lie on the same cylindrical envelope as the cylinder bore (18) itself, giving good, even support. However, none of the outer surfaces, outboard or inboard, present any concavities that would jeopardize the ability to form the piston (20) with only two forming elements that part in a straight line.

Abstract: An unbiased valve is located within a muffler. The valve is positioned by the pressure differential across the valve and is either in the full open or full closed position. A pressure equalization tube is provided between the downstream cavity of the muffler and the back of the valve such that flow pattern produced low pressure areas are avoided and the valve can react to actual pressure differentials in the flow.

Abstract: The profile of the valve stop of a discharge valve is configured such that the portion facing the free length of the valve member has a first fixed radius portion and a second, larger fixed radius portion. The first and second fixed radius portions are tangent at their transition.

Abstract: An angulating piston assembly for a vehicle air conditioning system compressor comprises a composite piston including a metal rod having a ball at a proximal end and a plastic head at a distal end. A piston ring subassembly is operatively received about the periphery of the plastic piston head. The subassembly is characterized by a rigid support collar molded into the piston head and a piston ring of low friction material stretched and snugly received over the collar. An integral molded lip on the piston head and an outwardly projecting skirt on the support collar maintain the piston ring in position. An inwardly projecting flange is provided on the support collar and molded into the plastic piston head to provide a lock to prevent relative axial movement between the support collar and the piston head.

Abstract: An assembly for providing socket plate torque restraint for a variable displacement wobble plate compressor includes a non-rotary Rzeppa joint. The joint has an outer race, an inner race, grooves in the races, a plurality of torque receiving balls and a cage for properly maintaining and positioning the balls in the grooves for operation. The joint is connected to an anti-rotational shaft. The shaft is mounted by the drive hub of the compressor to allow for translational axial and relative rotational motion. At least one key is received in a keyway in the anti-rotational shaft and a companion socket in the cylinder block fixed to the compressor housing. The Rzeppa joint provides the ideal kinematic restraint motion of the socket plate; the profile of the grooves on the inner and outer races and the cage having a curvature to effectively maintain the balls situated substantially in a single torque transmitting plane that bisects the joint angle.

Abstract: An assembly for enhancing piston stroke control for a variable displacement wobble plate compressor having basic differential gas pressure control includes a non-rotary shaft mounted to provide translational axial movement in the housing of the compressor. A helical compression spring biases the shaft and non-rotary socket plate in an upstroke direction towards full piston stroke operation. The upstroking force provided by the spring acts to compliment the internal refrigerant gas pressure to provide for improved control and stability for piston stroking. The socket plate is driven to nutate by a journal pivotally mounted on a central drive hub. The control assembly further includes a set of ears with outer flats that mate with inner flats on cooperating flanges of the drive hub. Pivot pins extending perpendicular to the direction of piston travel connect the ears of the journal with the flanges of the drive hub.

Abstract: A composite piston for an automotive air conditioning compressor is provided having an aluminum shank or piston rod, a reinforced plastic piston head and a steel ball for engaging a socket plate or the like. The shank has a distal end that has a slight reverse taper and a knurled surface for providing attachment to the plastic head that is molded thereon. The proximal end of the shank has a barrel to which the steel ball is press fitted. The shank is provided with a first collar adjacent the knurled distal end of the shank and a second collar adjacent to and intermediate the first collar and the proximal end of the shank. The first collar provides a seal for the mold cavity into which plastic is injected to form the piston head over the knurled surface of the shank. The second collar provides a support for the press fit operation of the steel ball onto the distal end of the shank.