Thermo King Corporation

Westinghouse Electric Corporation

Donald K Mayer

William A Forsty

A refrigerant compressor system suitable for transport refrigeration applications, including a refrigerant compressor, an electric motor and a hydraulic motor directly coupled together within a common housing. The electric motor includes a stator and a rotor, with the rotor having first and second axial ends. The refrigerant compressor is coupled to the first axial end of rotor, and the hydraulic motor is coupled to the second axial end. A single housing surrounds the electric motor, the refrigerant compressor, and the hydraulic motor. Hydraulic fluid for driving the hydraulic motor is selected to be compatible with the lubricating oil of the refrigerant compressor, such that leakage of hydraulic fluid into the housing will not adversely affect operation of the refrigerant compressor system. The housing is directly connected to a selected side of an associated refrigeration system, with the suction side being preferred, enabling the housing to also function as a refrigerant accumulator.

Compressor arrangement suitable for transport refrigeration systems

An oil separator suitable for separating oil from vaporized refrigerant leaving the high pressure discharge side of a refrigerant compressor, and for returning the separated oil to the compressor crankcase. The oil separator includes an elongated housing having a longitudinal axis. Oil separation stages and a capillary tube are disposed within the housing. The capillary tube has a first end into which oil may flow, and a second end in fluid flow communication with an oil return outlet on the housing. The first end of the capillary tube and the oil return outlet are positioned relative to one another such that the longitudinal axis of the housing may be oriented at any selected angle in a range of ninety degrees between horizontal and vertical orientations. The capillary tube has a bore and length selected such that a predetermined refrigerant flow rate is created which carries oil to the crankcase.

Oil separator for refrigeration apparatus

For a transport refrigeration unit having a refrigerant compressor 14 adapted to be driven alternatively by an engine 10 through belt 52, or by electric motor 12 through belt 58 has the clutch 36 mounted to the compressor 14 with both the engine 10 having a rigid pulley 38 on its output and the motor 12 having the rigid pulley 40 on its output.

Drive arrangement for compressor of a transport refrigeration unit

A refrigerant drier constructed to maintain compression of a desiccant to reduce the formation of refrigerant contaminating dust caused by attrition of the desiccant when the drier is used in applications subject to vibration. The desiccant is maintained in compression by a compression spring and barbed spring follower. Composite laminated filters are disposed adjacent to each end of the desiccant, with each composite filter including a fiberglass filter pad, which has excellent filtration characteristics for preventing any attrition dust which is generated from leaving either end of the drier. Each composite filter also includes a filter pad selected for durability which is disposed immediately adjacent to the desiccant, to cushion and protect the fragile fiberglass from aggressive action by the dessiccant. Annular perimeter rings are disposed between the dessicant and the composite filters to prevent desiccant migration past the outer perimeters of the composite filters.

Refrigerant drier

A combined refrigerant receiver, suction gas accumulator, and heat exchanger is provided and is particularly useful in connection with a transport refrigeration unit, and includes an internal concentrically disposed receiver 46 in the upper portion of an accumulator shell 40, the disposition providing an annular space 48 between the receiver and accumulator shell, in which is located a helically wound finned tube heat exchanger 56 which carries warm liquid refrigerant from the receiver to an outlet of the shell connected to an evaporator, with cold suction gas entering the shell at 52 and passing over the external fins 60 on the heat exchanger to exit the shell at 66.

Combination refrigerant receiver, accumulator and heat exchanger

A honeycomb assembly 32 located in the air discharge nozzle portion 30 of a transport refrigeration unit is movable from one position as shown in FIG. 2 in which the assembly functions as an airflow straightener and air throw increaser, to another position as shown in FIG. 4 in which the honeycomb assembly blocks airflow through the discharge nozzle and functions as a defrost damper.

Transport refrigeration unit combination airflow straightener and

In a transport refrigeration system of the type adapted to provide either heating or cooling, loss of refrigerant is detected by first and second sensors 58 and 60 located upstream and downstream, respectively, of the expansion device 34, and with the downstream sensor 60 also being downstream of the location at which hot gas is injected from line 56 to pass to the refrigerant coil 40 in a heating mode of operation. The arrangement includes means for both determining the mode of system operation, either heating or cooling, and comparing the differential temperatures sensed for determining the departures from ranges of temperatures normally expected with an adequate charge of refrigerant.

Refrigerant charge monitor and method for transport refrigeration system

This invention provides a direct oil return system from the accumulator tank in the refrigerant circuit of a transport refrigeration system to the crankcase of the compressor for returning oil entrained in the refrigerant to the oil sump. A pressure relief valve in the lubricating oil circulating system positively opens under the influence of oil pressure from the positive displacement oil pump whenever the compressor is operating to bleed excess oil from the pump back to the sump. The oil return line from the accumulator tank of the refrigeration system is connected to the valve to enter through another inlet port which opens in response to the pressure relief valve being opened and flows therethrough to another outlet in the valve also in communication with the sump. As the pressure relief valve and thus the inlet ports in the oil return line remain closed whenever the compressor is not operating, liquid refrigerant is unable to migrate therethrough to the sump and, in the heating mode of operation of the refrigerant system, which is the mode in which liquid refrigerant is most likely to be entrained in the returning oil, an external heat source heats the line draining the oil from the accumulator tank to vaporize the liquid refrigerant therein to prevent liquid refrigerant being returned to the sump when the compressor is operating.

Crankcase oil return valve

This invention provides a direct oil return system from the accumulator tank in the refrigerant circuit of a transport refrigeration system to the crankcase of the compressor for returning oil entrained in the refrigerant to the oil sump. A pressure relief valve in the lubricating oil circulating system positively opens under the influence of oil pressure from the positive displacement oil pump whenever the compressor is operating to bleed excess oil from the pump back to the sump. The oil return line from the accumulator tank of the refrigeration system is connected to the valve to enter through another inlet port which opens in response to the pressure relief valve being opened and flows therethrough to another outlet in the valve also in communication with the sump. As the pressure relief valve and thus the inlet ports in the oil return line remain closed whenever the compressor is not operating, liqid refrigerant is unable to migrate therethrough to the sump and, in the heating mode of operation of the refrigerant system, which is the mode in which liquid refrigerant is most likely to be entrained in the returning oil, an external heat source heats the line draining the oil from the accumulator tank to vaporize the liquid refrigerant therein to prevent liquid refrigerant being returned to the sump when the compressor is operating.

Crankcase oil return for a transport refrigeration system providing both

A readily removable and serviceable filter assembly in an oil recirculation path of a bearing lubrication system is shown wherein the oil passing through the bearing to lubricate the bearing surfaces is returned to an interior reservoir through a stationary passage having a replaceable bearing oil filter assembly of multiple interengaging components to form a generally unitary assembly.

Recirculating bearing oil filter assembly

Truck body mounted refrigeration unit

An electric motor and an in-line speed-responsive clutch are arranged so as to provide dual drive for selectively driving a refrigerant compressor by either an internal combustion engine or by the electric motor. The rotor of the electric motor is journalled for relative rotation on the output shaft of the engine, and the motor rotor can be driven through the clutch when the output speed of the engine output shaft exceeds a predetermined minimum. By having both power sources adapted to drive the compressor with the motor rotor journalled on the engine output shaft and by employing a single clutch, economy of parts, relative ease in assembly, and a more compact arrangement may be achieved.

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Bloomington, MN, United States of America

Donald K Mayer