Abstract: A valve return passage for quickly returning a valve to a closed position, includes return passages for communicating discharge pressurized fluid to a rear surface of a floating valve. The use of the return passages ensures that pressurized gas is communicated quickly to close the valve at shut down. This reduces the noise of operation of the compressor.

Abstract: A scroll compressor back pressure chamber seal protector is operable to prevent the seal from moving away from a separator plate during reverse rotation. During reverse rotation, a check valve associated with the seal communicates a higher pressure fluid into the back pressure chamber such that a low pressure from an intermediate pressure chamber will not pull the seal away from the separator plate. In this way, the seal is maintained in contact with the separator plate during reverse rotation.

Abstract: A vent is included into a scroll compressor for protecting a refrigerant system in the event of loss of charge. The vent selectively taps an entrapped compression chamber to a housing chamber which surrounds the motor. In the event of a low charge, the gas in the compression chamber will be at a high temperature, and will heat the motor when the vent opens. The vented heated gas will then actuate a temperature protection device on the motor, causing the motor to stop rotation. In further embodiments, the compression chamber which supplies the tapped fluid is the discharge port.

Abstract: A method of forming a drive surface on an eccentric pin of a drive shaft for a scroll-type compressor is provided. First, an eccentric pin having an axis and a generally cylindrical outer surface disposed radially about the axis is provided. Next, a broaching tool having a machining face with a contour is provided. The contour may be a concave shallow bell-shaped curve. Finally, the drive surface is formed by engaging the outer surface with the machining face transverse to the axis. In this manner, the machining face forms a shape complementary to the contour on the eccentric pin thereby forming a slight crown on the drive surface. The broaching tool produces an adequate surface finish so that no subsequent machining operations to the drive surface are necessary.

Abstract: An improved efficiency economizer system for compressors incorporates the use of a check valve blocking return flow into the economizer return line. The economizer return line communicates with an economizer port, which communicates with a compression chamber. Pressure in the compression chamber can vary during the operational cycle of the compressor. Thus, in the past, there has sometimes been backflow of refrigerant through the economizer injection port and into the return line. The present invention prevents this backflow. Most preferably, the invention is utilized on scroll compressors; however, other types of compressors may benefit from this invention.

Abstract: A scroll compressor assembly incorporates a separator plate which has a clearance between its outer periphery and an inner periphery of an end cap. In this way, the location of the separator plate along the center axis of the scroll can be adjusted. Further, the separator plate is placed on the center shell prior to attachment of the end cap. Thus, the separator plate need not be welded to the end cap as in the prior art. Problems such as weld splatter thus eliminated.

Abstract: A scroll compressor is provided with structure that allows a reduction or modulation in mass flow capacity. Structure is provided for controlling the back pressure force tending to bias one scroll into other. This structure defines two distinct back pressure chambers. Pressure fluid is not supplied to at least one of the back pressure chambers during modulated operation.

Abstract: A scroll compressor is assembled by force-fitting the pump unit and the lower bearing into the generally cylindrical outer housing. The force-fit holding strength is increased by providing both the crankcase and the bearing support with cylindrical portions. Thus, force-fit holding strength is provided over the entire periphery of the elements. The structure preferably takes the outer housing beyond its plastic yield point, also increasing the hold strength. In this way, the relatively simple method of force-fitting may be utilized to assemble the scroll compressor, while still achieving acceptable holding force.

Abstract: A scroll compressor has a valve normally closed during forward operation of the scroll compressor. Upon reverse rotation, force imbalances allow the valve to open and communicate a chamber downstream of a check valve to a chamber upstream of the check valve. By communicating these two chambers, the detrimental effects of reverse rotation are reduced or eliminated. Two valve embodiments are disclosed. One embodiment also relieves unduly high discharge pressures. In a third embodiment, a pressure relief valve is provided to prevent desirably high pressure ratios or pressure differentials.

Abstract: A scroll compressor having an apparatus for minimizing oil leakage during reverse running is provided. The compressor includes a suction tube for allowing gas to enter the compressor housing. One oil minimizing apparatus is a check valve disposed at the suction tube having a spring normally biased against the inlet suction tube so as to prevent oil from exiting the suction tube during reverse running of the motor of the compressor. An alternative oil minimizing apparatus is an oil dam extending longitudinally above the suction tube on an inner surface of the compressor housing. The oil dam bends circumferentially with the inner surface for draining oil along the inner surface away from the suction tube.

Abstract: A scroll compressor is provided with structure that causes the wraps to move out of engagement when reverse rotation occurs. An eccentric pin and slider block are constructed such that when forward rotation is occurring, flat surfaces on the pin and slider block are brought into contact to drive the slider block and hold the wraps in engagement. However, when reverse rotation occurs, the flat surfaces move out of engagement. The slider block has a pivot point which moves into contact with the eccentric pin. The slider block pivots relative to the eccentric pin, and the wraps of the scroll members are brought out of engagement.

Abstract: A counterweight is attached to a rotating shaft by a slip fit, combined with two axially abutting surfaces to hold the counterweight. The counterweight is preferably held at one face by a ledge formed on the shaft, and at the opposed face by a portion of the motor rotor. Circumferentially spaced abutting surfaces also hold the counterweight to cause the counterweight to rotate with the rotor. The present invention eliminates the need for separately attaching the counterweight to the shaft, and thus reduces both the complexity of assembly, and also the need for precise manufacturing tolerances for the counterweight.

Abstract: A scroll compressor is provided with a reverse rotation detection circuit that monitors the temperature adjacent the suction tube. An elevated temperature at the suction tube is indicative of reverse rotation, and if the temperature exceeds a predetermined maximum, then a determination is made that reverse rotation is occurring. Once this determination is made, the rotation of the motor is stopped, or corrected.

Abstract: An improved seal for use in scroll compressors incorporates a slanted coil spring. In the prior art, generally C-shaped leaf springs have been utilized. The slanted coil spring has better survivability against operational extremes than the prior art.

Abstract: An improved housing for scroll compressor has the end cap housing formed integrally with the fixed scroll member. The end cap housing is preferably welded to a tubular housing enclosing the scroll compressor. Most preferably, the end housing has inner and outer tubular portions and the tubular housing extends upwardly into a channel between the inner and outer tubular portions. A muffler is preferably formed integrally with the end cap and extends to a side of the end cap. The present invention further includes heat transfer fins extending from the end cap. The positioning of the muffler to the side decreases the overall length of the compressor. The use of the fins increases the efficiency of compression as heat is removed from the compression chambers. The use of the unique combined end cap and fixed scroll which is welded to the tubular housing simplifies assembly.

Abstract: A series of check valves are disclosed for use in a scroll compressor which control and dampen the closing of the check valve to reduce noise during rapid pressure fluctuations encountered during normal operation and to control loss of gas in a discharge passage. In one check valve, a reed valve or poppet valve is employed to control the motion of a main valve to a closed position. In another check valve, suction pressure is used to reduce the closing force of the main valve. In another check valve, the main refrigerant flow passes through a converging, diverging passage to create a relatively low pressure chamber to reduce the closing force of the main valve. In another check valve, the reverse flow from the discharge plenum either does not act to close the valve or acts on a reduced surface area.

Abstract: A unique valve assembly is disclosed which has particular utility in scroll compressors. The valve assembly includes a relatively thin valve plate formed of reed valve steel. The valve plate is less than 0.05 inch, and is elastically deformable upon application of fluid pressure. Thus, the pressure fluid in a chamber formed above the valve plate deforms the valve plate to conform to the valve seat. In embodiments a clip holds the valve plate on the valve seat. The clip provides a stop surface for the valve seat, and is also formed of thin resilient steel. Thus, when the valve plate is driven to its open position, the steel valve plate contacts the steel clip such that there is a spring back effect in response to rapid movement of the valve plate to its open position.

Abstract: A scroll compressor has a fixed scroll and an orbiting scroll nested with one another within a shell. The orbiting scroll has a base plate with a pair of opposed slots formed therein, and a spiral wrap extending axially from the base plate. The fixed scroll has a base plate and a spiral wrap extending axially from the fixed scroll base plate nested with the spiral wrap of the orbiting scroll. A pair of towers extends axially downwardly from the fixed scroll base plate, each tower having a slot formed therein, diametrically opposed from the slot formed in the other tower. An Oldham coupling has an annular ring with an irregular oval profile which closely follows the outermost radial surface of the spiral wraps as the scroll compressor operates. The Oldham coupling also has an asymmetric shape with respect to any vertical plane bisecting a central axis of the Oldham coupling. A pair of opposed keys extend axially from a first surface of the Oldham coupling slidingly engaging the slots in the towers.

Abstract: A scroll compressor of the type having a cantilever mounted shaft is provided with a carbon crankcase bearing. Further, the bearing mounting the eccentric pin within the orbiting scroll is also formed of a carbon material. The bearing mounting the lower end of the shaft is further formed of the carbon material. The carbon bearing insures that the shaft will be quickly worn away should there be shaft misalignment.

Abstract: A scroll compressor of the type having a cantilever mounted shaft is provided with a carbon crank case bearing. The carbon bearing insures that the shaft will be quickly worn away should there be shaft misalignment.