Abstract: The front cover of a transport refrigeration unit includes a plurality of hinged access doors, with each door being formed of a pair of spaced thermoplastic olefin sheets with their edges being bonded along the entire periphery of the door to form a hollow space between the sheets without a need for foam. The edges are bonded by a thermoforming process which provides strength and rigidity to the door. Additional thermoforming bonds are made at locations other than the periphery to provide further strength and rigidity. A ribbing structure is formed in one of the sheets and extends around the periphery thereof. Further ribbing may extend transversely across the sheet in non-peripheral positions.

Abstract: A blower wheel housing for an air conditioning system is formed of a single molded element having a base section and a nozzle section with included vanes having complex shapes. This is accomplished by employing a pair of mold core elements which together form a cavity into which a plastic material is injected to form the cover with its integral nozzle and vanes, and the mold core elements are then withdrawn in opposite directions but at an angle to the direction normal to the two mold core elements to thereby accommodate the complex shapes of the vanes. In one embodiment, the top wall of the nozzle is disposed at an acute angle to the longitudinal plane of the cover, and the mold core elements are also withdrawn in a plane that is parallel to this wall.

Abstract: The front cover of a transport refrigeration unit includes a plurality of hinged access doors, with each door being formed of a pair of spaced thermoplastic olefin sheets with their edges being bonded along the entire periphery of the door to form a hollow space between the sheets without a need for foam. The edges are bonded by a thermoforming process which provides strength and rigidity to the door. Additional thermoforming bonds are made at locations other than the periphery to provide further strength and rigidity. A ribbing structure is formed in one of the sheets and extends around the periphery thereof. Further ribbing may extend transversely across the sheet in non-peripheral positions.

Abstract: A transport refrigeration system includes a single frame for containing both a refrigeration condenser coil and an engine coolant radiator arranged in serial airflow relationship within a framework. Either one or the other may be removed and replaced without replacing the other.

Abstract: A modular condenser fan/motor assembly for use in a transport refrigeration system includes a support frame, a fan shroud panel, a fan/motor assembly and a support bracket. A fan and motor assembly for use in a transport refrigeration unit includes a fan impeller disposed about an inside/out motor, whereby the fan impeller rotates with at least a portion of an outer casing of the motor.

Abstract: A blower wheel housing for an air conditioning system is formed of a single molded element having a base section and a nozzle section with included vanes having complex shapes. This is accomplished by employing a pair of mold core elements which together form a cavity into which a plastic material is injected to form the cover with its integral nozzle and vanes, and the mold core elements are then withdrawn in opposite directions but at an angle to the direction normal to the two mold core elements to thereby accommodate the complex shapes of the vanes. In one embodiment, the top wall of the nozzle is disposed at an acute angle to the longitudinal plane of the cover, and the mold core elements are also withdrawn in a plane that is parallel to this wall.

Abstract: Fresh air exchange is achieved by uncovering two ports which, respectively, allow stale air to leave the trailer through a high pressure duct and fresh outside air to enter the trailer through a low pressure duct. The trailer end of the ducts are connected to the refrigeration unit evaporator section where the evaporator fan provides the pressure differential. The opposite ends of the ducts are connected to a bracket mounted on the refrigeration unit frame and are exposed to the outside fresh air through a hole in the refrigeration unit's grille when the cover over the ducts has been opened by the linear solenoid under the control of the microprocessor.

Abstract: A refrigeration unit is provided with a manually operated fresh air vent made up of a cap assembly and a handle assembly which move together in a linear/axial direction. The handle assembly is rotatable to change the position of the fresh air vent. The fresh air vent controls both the providing of fresh air to the circulating air in the trailer and the exhausting of a portion of the circulating air. The evaporator fan is run continuously when the air vent is open to prevent the build up of gases produced by the perishable cargo.

Abstract: A sound suppression system for suppressing the noise of an engine within an enclosure of an outdoor unit for a transport refrigeration system. A resonator is provided to suppress noise caused by the inflow of air to the air intake manifold of the engine, and a sound panel is provided in the bottom wall of the enclosure to suppress noise emanating from the engine. The resonator and the sound panel are co-located in the same plane and are preferably integrally formed of a molded plastic material.

Abstract: A trailer refrigeration unit has a pivotally mounted engine driven generator unit and a pivotally mounted compressor unit that combine to form a structure that minimizes the spatial "real estate" occupied by the refrigeration unit. A single common rotatable shaft operates the integrally mounted engine and generator to form a unitary unit. The engine driven generator and compressor units can be pivoted out of the refrigeration unit frame to a fully serviceable position that provides easy access to the rear portions of the engine, generator and compressor units without requiring removal of those units from the refrigeration unit.

Abstract: According to the present invention a transport refrigeration unit of the type adapted to be mounted on the front wall of and for conditioning the interior of a trailer is provided with a front cover adapted to be attached to a structural framework of the refrigeration unit. The cover includes a plurality of sections formed from a single thickness of polyethylene and also includes a plurality of sections formed from a composite structure. According to a preferred embodiment the composite structure is a twin sheet structure filled with a polyurethane foam. The composite structures comprise doors which are adapted to be hingedly mounted to the refrigeration unit. The hinges are attached to the composite structure by a combination of an interior and exterior support plate arrangement whereby one skin of the twin sheet structure is sandwiched between the plates.