Abstract: A counterweight is connected to a driving shaft through a lost motion connection. The shaft is received in a bearing relationship in a fixed member. An axially extending portion of the counterweight coacts with the fixed member to define a pair of chambers which radially vary such that the chambers taper convergingly in a circumferential direction corresponding to the normal direction of rotation of the shaft. Cylindrical pins are located in the chambers and provide a jamming relationship between the counterweight and the fixed member when said shaft tends to rotate in a reverse direction.

Abstract: In a scroll compressor, under conditions favoring reverse operation, the scroll wraps are separated so as to provide a continuous, unimpeded path through the scrolls. Spring bias, a repositioning of driving contact areas and/or force areas can be used singly or in combination to cause separation of the wraps.

Abstract: Rolling element bearings are located between the eccentric drive pin and the slider block of a scroll compressor. The rolling elements reduce static or boundary lubrication friction by an order of magnitude in providing rolling friction. As a result, movement of the orbiting scroll into and out of flank contact is facilitated and scroll separation takes place earlier in the shutdown process.

Abstract: An eccentric drive pin is located on the overhung end of a crankshaft. The drive pin is located within a bore in a slider block which is located within the hub of an orbiting scroll. Either the drive pin or the slider block bore has an axially curved surface and the other has a corresponding flat surface parallel to the axis of the crankshaft. Contact between the axially curved and corresponding flat surface remains at essentially the same axial location even though the drive pin is deflected under loading.

Abstract: Improved axial compliance in a scroll compressor 10 between a fixed scroll 11 and an orbiting scroll 13 is achieved by providing at least one dynamic back pressure chamber 25 disposed behind the orbiting scroll 13. A pressurized fluid is bled from a selected one of compression pockets 19 through a port 21 formed in the orbiting scroll 13 into the dynamic back chamber 25 to provide varying on sub-cycle basis back pressure to reduce friction between the fixed and orbiting scrolls. A static back pressure chamber 27, also disposed behind the orbiting scroll 13, may be provided into which pressurized fluid is bled from a selected one of the compression pockets 19 to provide an additional back pressure on the scroll 13 which is substantially constant over the cycle.

Abstract: A thermally responsive valve establishes a discharge to suction bleed responsive to the actuation of a thermal actuator. The thermal actuator is responsive to the temperature of the floor of the fixed scroll in a region near the outlet so that the actuator is responsive to local conditions indicative of impending failure.

Abstract: A pressure ratio responsive valve is provided to control a discharge to suction bypass in a scroll compressor. The valve is acted on by suction pressure, discharge pressure and an intermediate pressure. When the compressor is operating at too high of a pressure ratio, the valve is opened to create a discharge to suction bypass.

Abstract: Seal structure for a scroll compressor is provided with localized magnetic surfaces. The seal is carried by one member and the magnetic surface coacts with a facing ferromagnetic surface to provide a seal therebetween even when the members are axially displaced and where there is orbiting motion therebetween.

Abstract: One or more eccentrically located pressure pockets are defined between the orbiting scroll and a seal plate. The seal plate and pockets rotate while the orbiting scroll orbits. The pressure in the pockets provide a restoring moment relative to the overturning moment provided by the gas forces in addition to providing an axial bias for axial compliance. Because the moment is balanced, a reduced axial biasing force is necessary and thereby wear and friction losses are reduced. In the preferred embodiment, the seal plate is integral with the slider block.

Abstract: A back pressure chamber seal for use in a scroll type compressor that is located between the adjacent surface on the back of the orbiting scroll and the machine casing. Seals are loosely received in endless grooves formed in one of the two adjacent surfaces and are magnetically held in contact against the other adjacent surface and one wall of the groove to provide a sealed region. A pressurized fluid is delivered into the sealed region to provide an axially disposed biasing force acting against the orbiting scroll.

Abstract: A scroll-type compressor or other rotating machine employs a crankshaft having an integral counterweight to compensate for the off-axis orbiting motion of the device's orbiting scroll. The crankshaft is unitarily formed with a generally cylindrical crank portion at an upper end of the shaft, and with the counterweight formed immediately adjacent the crank. The counterweight is preferably in the form of a segment of a cylinder of smaller radius than that is disposed within the radius of the cylindrical passage of the stator. This permits the rotor and shaft assembly, with counterweight, to be assembled from below after installation of the stator.

Abstract: Two annular pressure pockets are used to push the orbiting scroll against the fixed scroll to minimize leakage. One pocket is at intermediate pressure and the other is at discharge pressure. The pockets are defined by the orbiting scroll and an axial ring. In the preferred embodiment inner and outer seals are carried by the axial ring and an intermediate seal is carried by the orbiting scroll whereby the pressure pockets are of an eccentric configuration.

Abstract: A scroll-type hermetic compressor is disclosed including a compressor mechanism having a fixed scroll member. The fixed scroll member includes a plate portion that is subject to forces causing deflection thereof. A housing cover plate is attached to the back surface of the fixed scroll member so as to define a discharge pressure chamber therebetween for exposing a partial area of the back surface to compressed refrigerant fluid. The discharge pressure chamber also serves as a discharge muffler. Also disclosed is a method of assembling a compressor wherein a compressor mechanism is mounted to a top cover plate before the top cover plate is attached to an open-ended shell to form a hermetically sealed housing. The compressor mechanism is suspended from the top cover plate and extends into the interior of the housing.

Abstract: A scroll-type hermetic compressor is disclosed including within a hermetically sealed housing a fixed scroll member, an orbiting scroll member, a main bearing frame member, and a crankshaft. An oil sump is located in a discharge pressure chamber in the housing. The crankshaft is journalled by bearings in the frame member and the orbiting scroll member. A centrifugal oil pump supplies lubricating oil from the sump to the bearings through an axial passageway in the crankshaft. A vent allows the pumped oil to return to the sump to reduce leakage of oil and refrigerant into regions at suction pressure.