Abstract: A control system is provided that can identify the occurrence of a single surge cycle in centrifugal compressor using various methods and devices. Once the occurrence of a single surge cycle is identified, the control system can take remedial action to respond to the surge cycle, such as by adjusting the position of a variable geometry diffuser, and restore the centrifugal compressor to stable operation.

Abstract: A control system is provided that can identify the occurrence of a single surge cycle in centrifugal compressor using various methods and devices. Once the occurrence of a single surge cycle is identified, the control system can take remedial action to respond to the surge cycle, such as by adjusting the position of a variable geometry diffuser, and restore the centrifugal compressor to stable operation.

Abstract: The tunable resonator is coupled to the engine speed control such that the resonator is set to a different frequency range when the engine speed is changed. The frequency range is changed by opening and closing necks and/or changing the effective volume of the resonator.

Abstract: A compressor for compressing refrigerant in an air conditioning or refrigeration system, including a housing having a suction port, a discharge port, and a compression chamber, a mechanism for producing a compression cycle for compressing the refrigerant, wherein the compression cycle occurs in the suction port, discharge port and compression chamber, and a mechanism for providing liquid refrigerant into the compression cycle at a desired location for reducing pressure pulsations and associated radiated noise produced during the compression cycle.

Abstract: The tunable resonator is coupled to the engine speed control such that the resonator is set to a different frequency range when the engine speed is changed. The frequency range is changed by opening and closing necks and/or changing the effective volume of the resonator.

Abstract: A compressor for compressing refrigerant in an air conditioning or refrigeration system, including a housing having a suction port, a discharge port, and a compression chamber, a mechanism for producing a compression cycle for compressing the refrigerant, wherein the compression cycle occurs in the suction port, discharge port and compression chamber, and a mechanism for providing liquid refrigerant into the compression cycle at a desired location for reducing pressure pulsations and associated radiated noise produced during the compression cycle.

Abstract: The tunable resonator is coupled to the engine speed control such that the resonator is set to a different frequency range when the engine speed is changed. The frequency range is, changed to a higher frequency by closing a valve which effectively reduces the length of the resonator.

Abstract: An annular isolator is provided having a metal tube which acts as a spring while defining a flow path and a resilient member located between two loading plates. The resilient member supports the weight of one of the members being coupled and the tube acts as spring as to transmitting vibration.

Abstract: A metal diaphragm is provided which acts as a spring while defining a flow path. A restraint limits upward movement of the diaphragm during transient motion. Downward movement is resisted by a Belleville spring.

Abstract: The air drawn into a diesel engine serially passes through a filter and a cavity, which acts as an acoustic attenuator, before being supplied to the cylinders of the diesel engine. In the cavity the air is in a heat transfer relationship with a heat sink for the electronic components of a microprocessor control. The electronic components may be located in the plenum cavity or in a separate chamber but must have a heat transfer relationship with the cavity, such as through a common wall on which the electronic components are mounted. A heat sink may extend into the cavity.

Abstract: The open grille structure normally directly in front of a condenser coil is replaced with an acoustical barrier which is moved forward of the condenser coil. In moving the acoustical barrier forward, space results at the top, bottom and sides of the unit which can be used to provide inlet openings for inlet air. Acoustical absorption material lines the structure defining the air flow path to the coil. The modified air flow path results in a modified sound path which results in sound attenuation.