Abstract: A scroll compressor has a sealed housing. Within the sealed housing is a first scroll member having a first base and a first generally spiral wrap extending form the first base. A second scroll member has a second base and a second generally spiral wrap extending from the base. The wraps of the first and second scroll members interfit to define compression chambers. A motor drives the second scroll member to orbit relative to the first scroll member. A valve controls the communication of gas between the compression chambers and a discharge pressure chamber. The valve is retained within a valve chamber of the first scroll member. A valve retainer is used to keep the valve within the valve chamber. The valve retainer is attached to the first scroll member by a snap fit connection.

Abstract: A unique positioning of a discharge tube relative to a pivot axis of a check valve in a compressor reduces the wear and fatigue stresses on the pivoting check valve components. The tube is centered on an axis that is non-perpendicular to an axis that is parallel to the pivot axis of the check valve, and in one embodiment was at 45°. With the inventive positioning of the discharge tube relative to the pivot axis, the flow streamlines heading from the discharge port to the discharge tube are no loner normal to the flapper valve surface, and the amount of wear between moving valve components and fatigue stresses are reduced.

Abstract: A scroll compressor has a novel slider block with an upper surface that extends for a greater extent than the prior art. By extending this upper surface, the upper surface is better able to withstand wear on the slider block during the life of the scroll compressor.

Abstract: A scroll compressor is provided with economizer injection ports, which extend through the wrap of one of the scroll members. Preferably the injection ports are formed through a so-called “hybrid” wrap, which has a varying thickness. The other scroll member is provided with grooves in its base plate. The injection of economizer fluid occurs only during a portion of the orbiting cycle when the injection port and corresponding grooves are aligned with each other. An indentation is formed into the wrap that includes the injection port. The indentation is spaced circumferentially from the injection port. The indentation communicates with the groove, such that refrigerant can pass from the injection port, into the groove, and through the indentation into a compression chamber. This increases the injection time allowing more fluid to be injected into the compression chamber, and provides the scroll compressor designer with greater freedom to achieve desired flow of economizer fluid into the compression chambers.

Abstract: An abradable coating is formed on portions of the flank wall of the wraps of a scroll compressor. The radially outer portions of the flank wall are left uncoated, and can bear a force between the scroll wraps. In this manner, the load is not transferred through a coated portion, but rather through the uncoated portion. As the scroll wraps move relative to each other at run-in, the abradable coating wears away leaving a tight fit between the flank walls at the radially inner locations.

Abstract: Compressor performance is affected by the size of an economizer or by-pass port area. To achieve variation in size, an insert is inserted into an economizer and/or unloader flow passage to provide a desired port area. The insert may be selected from a number of available insert sizes having different sized openings. In this way, a compressor designer can minimize machining time by keeping same flow passage geometry for different compressor sizes and applications.

Abstract: Several transmission embodiments selectively communicate rotary drive to an orbiting scroll to achieve capacity modulation. In these embodiments, when the motor is driven in a first direction, the orbiting scroll is driven at a rate which is equal to the motor speed. However, if the motor is driven in a reverse direction, the orbit rate of the orbiting scroll is reduced. The transmission ensures that the orbiting scroll member itself is driven in the proper forward direction regardless of whether the motor is being driven in forward or reverse.

Abstract: A compressor assembly comprises a compressor, a motor protector, and a signaling device. Upon an overload condition, the motor protector activates. The signaling device also activates to serve as an alert that the compressor is not malfunctioning but instead is in an overload condition.

Abstract: A scroll compressor has an eccentric pin that extends forwardly of a rotating shaft. The eccentric pin generally has a curved outer portion and a flat outer portion. Each of the flat and curved outer portions have fillets that are formed to merge the eccentric pin portions into an end surface or shoulder on the shaft. The fillets are formed to have a relatively complex shape with more than a single radius of curvature. In one embodiment, there are two radii of curvature, with a greater radius of curvature formed to extend from an outer periphery of the eccentric pin, and merge into a second portion having the lesser radius of curvature that merges from the first portion downwardly into the shoulder. In a second embodiment, the fillet generally has the shape of one quarter of an ellipse.

Abstract: A method of aligning a crankcase to a non-orbiting scroll includes the steps of forming initial alignment surfaces on both the non-orbiting scroll and the crankcase. Further, when the non-orbiting scroll and the crankcase are machined, precision drilled holes are drilled into each of the two. These holes are drilled relative to datum surfaces on both the non-orbiting scroll and the crankcase. Thus, once the two have been pre-positioned, the precision drilled holes are aligned and a threaded bolt is inserted into the precision drilled holes. The threaded bolt ensures that the two will be radially positioned properly relative to each other.

Abstract: A self-modulating scroll compressor includes a pair of valves. A first valve moves to a low capacity position when the pressure differential is below a predetermined amount. A second valve moves to a low capacity position when the suction pressure is above a predetermined amount. Low capacity operation will only occur when both valves are open. The present invention thus provides a scroll compressor design with the ability to self-modulate and control the conditions under which low capacity operation occurs based upon two criteria.

Abstract: A scroll compressor has a recess cut into a surface of a crankcase or an orbiting scroll while there is no material removed next to the seals that seal refrigerant in the back chamber located between the orbiting scroll and crankcase. Because there is no material removed next to the seals, the gap between the orbiting scroll and crankcase remains intact in the sealing area and the seals continue to operate properly preventing the refrigerant leakage through the gap. In this case, the dimensional tolerances of the crankcase and orbiting scroll surfaces need only be tightly controlled in the area adjacent to the seals. The surface areas away from the seals do not require tight tolerance control, thus manufacturing and assembly is simplified and possibility of interference due to small gap between orbiting scroll and crankcase is avoided. In the preferred embodiment, the recess is introduced into the back chamber surface area of the crankcase.

Abstract: A compressor diagnostic system incorporates a control which receives a plurality of data streams about various operational features of the compressor. As an example, both temperature and pressure of the suction and discharge refrigerant are taken and sent to the control. Moreover, information with regard to the power being supplied to the motor is taken and stored. All of this information is utilized at a control which compares the information to expected values and determines a fault based upon the evaluation. Moreover, in another feature of this invention, much of this data is stored, and maintained at the compressor. In the event of a compressor failure, this stored information will provide a maintenance worker with a good indication of why the compressor failed.

Abstract: Low voltage electrical power is supplied to a diagnostic control device in a sealed compressor. Electrical power is tapped from a high voltage power line and transformed to low voltage power that in turn operates the diagnostic control device. The diagnostic control device and the electric voltage transforming system are housed within the sealed compressor shell, thus eliminating the need for additional openings in the compressor shell. Other low voltage devices can be powered in this way.

Abstract: Scroll compressors include a tap for communicating a compressed refrigerant to a back pressure chamber to resist a separating force. A restriction is placed within this tap to slow build-up of the back pressure chamber at start-up. Further, the restriction smoothes out any fluctuations in the back pressure force as the pressure in the compression chamber from which the refrigerant is tapped may fluctuate.

Abstract: A scroll compressor includes a protection device that has a valve movable between a position blocking flow from the back pressure chamber into the suction chamber, and a position allowing such flow. The valve is movable dependent on an oil temperature. Under adverse conditions, the oil will reach higher temperatures and the valve will open allowing flow of refrigerant from the back pressure chamber into the suction chamber. This refrigerant will likely be at an elevated temperature, and will assist the heated oil in moving a motor protection switch associated with the motor to shut down the motor. Moreover, by relieving the back pressure chamber, the two scroll members are allowed to move out of contact with each other, thereby reducing potential damage due to the adverse conditions.

Abstract: A scroll compressor is provided with a non-circular back pressure chamber which is still concentric about a center axis of the compressor, such as the center axis of the drive shaft. Stated another way, an inner seal and an outer seal define a back pressure chamber. The two seals are concentric, but at least one of the seals is non-circular. In this way, reduced a back pressure chamber can be provided while still allowing the amount of orbital movement necessary for the tap for communicating a compressed refrigerant to the back pressure chamber.

Abstract: A scroll compressor is provided with a generally spiral wrap having an abradable or conformable coating on radially inner portions of its tip. The coating is not applied to radially outer portions. During operation of the scroll compressor, the coating will eliminate tip gap leakage adjacent radially inner, higher discharge pressure portions of the compression process. The outer, non-coated portions will bear the axial load, and ensure the coating will not wear away to an undue amount.

Abstract: A self-modulating scroll compressor includes a pair of valves. A first valve moves to a low capacity position when the pressure differential is below a predetermined amount. A second valve moves to a low capacity position when the suction pressure is above a predetermined amount. Low capacity operation will only occur when both valves are open. The present invention thus provides a scroll compressor design with the ability to self-modulate and control the conditions under which low capacity operation occurs based upon two criteria.

Abstract: A scroll compressor has lubricant flow which communicates lubricant onto a motor protector when adverse conditions are present causing the motor protector to trip the motor and stop further rotation. The lubricant is returned to an oil sump through a normal return path. The normal return path outlet may be positioned above the motor protector such that lubricant will contact the motor protector when adverse conditions are present, or the outlet may be remote from the protector. When the outlet is remote from the protector, a funnel and tubing divert the oil to the motor protector under adverse conditions. Alternatively, a passage communicating with the normal return path is selectively blocked when an adverse condition is present. At that time, lubricant is forced into an alternative oil path, which is positioned above the motor protector.