The invention relates to transport temperature control units, and more particularly to undermount transport temperature control units for trucks or trailers.
Straight trucks and tractor-trailers (hereinafter referred to as “vehicles”) frequently transport cargo that must be maintained at a predetermined temperature during transportation in order to preserve the quality of the cargo. Vehicles that transport such temperature-sensitive cargo have a conditioned space that is maintained at a predetermined temperature by a temperature control unit mounted to the vehicle at a location either on the front of the cargo box or underneath the cargo box. These temperature control units are respectively referred to as nosemount and undermount transport temperature control units.
Undermount units are used when vehicle tilt cab clearance cannot be provided by a nosemount unit, when a nosemount unit cannot be provided for a drawbar trailer, or when the weight of a nosemount unit causes the vehicle to become unstable. Some countries, including Japan, have specific regulations mandating the use of undermount temperature control units under certain circumstances.
An undermount temperature control unit has three basic parts—a condenser module located underneath the cargo box, an evaporator module located inside the cargo box, and an installation kit that connects these modules. When the undermount temperature control unit is electrically powered, it also has a fourth part—an auxiliary alternator located in the vehicle's engine compartment. The auxiliary alternator is connected to a control box that is typically housed in the condenser module.
This invention is directed to condenser module of an undermount temperature control unit. Those skilled in the art commonly use the terms “condenser module” and “undermount temperature control unit” interchangeably when referring to the portion of the unit mounted underneath the cargo box. Therefore, unless otherwise specified below, the term undermount temperature control unit and condenser module will be used interchangeably.
Prior-art undermount temperature control units suffer from various disadvantages. First, typical undermount temperature control units are quite large, making them difficult to install in light of the space constraints underneath the vehicle created by fuel tanks, battery boxes, and the like. The relatively high weight of the undermount units also adds to the installation difficulties.
Once installed, typical undermount temperature control units are usually difficult to service due to the restricted access caused by the fuel tanks, battery boxes, and other equipment mounted underneath the vehicle. The layout and design of the components inside the unit also makes servicing some of the interior components difficult. For example, the numerous belts and pulleys on the diesel engine make accessing adjacent components extremely difficult. The frequency at which servicing is needed is also relatively high due to inadequate debris screening by the unit's housing.
While operating, typical undermount units are relatively loud and experience high levels of vibration, due largely to the components used in the unit. The three largest noise and vibration contributors are the diesel engine, the piston-type compressor, and the condenser fans commonly used in typical undermount units.
Typical undermount units are also known to have obstructed condenser air discharge pathways, often resulting in reduced capacity and efficiency of the unit. This reduced efficiency adds to the already high fuel consumption of the diesel engine. The air discharge pathways are often obstructed by the vehicle frame. The obstructions often divert the discharge air toward the ground, resulting in the blowing of dust and debris that can collect inside the unit. This dust and debris collection adds to the servicing problems described above.
It is therefore desirable to design an undermount temperature control unit having features that reduce the size and weight of the unit, that improve serviceability of the unit, that reduce noise and vibration of the unit, that provide improved condenser air discharge, and that reduce fuel consumption. The present invention provides such an improved undermount temperature control unit.
More specifically, the invention provides a condenser module for an electric temperature control unit for a transport vehicle. The condenser module includes a frame defining an interior space and having a first side and a second side opposite the first side. The condenser module also includes an access panel movably coupled to the first side of the frame for granting access to the interior space. A compressor is supported by the frame in the interior space. A refrigerant routing system communicates with the compressor and is also supported by the frame in the interior space. Additionally, a substantially U-shaped condenser coil is supported by the frame in the interior space and communicates with the refrigerant routing system.
In one aspect of the invention, the U-shaped condenser coil includes a base portion adjacent the first side of the frame, and first and second arm portions extending toward the second side of the frame. The base portion and the arm portions together define a second interior space within the interior space defined by the frame. An air displacement device is housed in the second interior space for moving air through the second interior space. The air displacement device is preferably an electrically-powered radial blower.
In another aspect of the invention, the condenser module includes a control box adjacent the first side for providing electric power to the unit. The control box is movably coupled to the frame and is movable between a first position, where the control box is inside the interior space and positioned for operation of the temperature control unit, and a second position, where the control box is at least partially outside the interior space and positioned to grant access to the refrigerant routing system and the compressor from the first side of the frame.
In yet another aspect of the invention, the compressor and the refrigerant system are both mounted on a single platform such that the compressor and the refrigerant routing system together define a single modular assembly that can be inserted or removed as a unit.
The invention also provides a method of gaining access to components housed in an interior space of a condenser module of a temperature control unit. The condenser module includes a frame with first and second sides, and a control box movably coupled to the frame adjacent the first side. The components include a compressor supported by the frame in the interior space adjacent the second side and a refrigerant routing system communicating with the compressor and supported by the frame in the interior space adjacent the second side.
The method includes moving the control box from a first position, where the control box is inside the interior space and positioned for operation of the temperature control unit, to a second position, where the control box is at least partially outside the interior space and positioned to allow access to the refrigerant routing system and the compressor from the first side of the frame. In one aspect of the invention, moving the control box includes rolling the control box out of the interior space and subsequently pivoting the control box so that at least a portion of the control box moves away from the first side of the frame.
Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims, and drawings.
Before one embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.
As best seen in
Referring now to
The unit 14 also includes a left side cover panel 94 coupled to the left side of the frame 70. The cover panel 94 includes a vent portion 98 that covers an air inlet opening 102 (see
The unit 14 also includes a right side cover panel 114 (see
The unit 14 further includes a front access panel 126 hinged to the front side of the frame 70 at hinges 130. As seen in
As will be described in more detail below, the front access panel 126, in combination with several other features of the unit 14, provides ready access to virtually all of the key components housed in the interior space 72. This ready access from the front side 54 is highly advantageous since, as seen in
Referring to
The undermount temperature control unit 14 is part of the refrigeration system used to condition the air in the box 22. The interior space 72 of the frame 70 houses a plurality of components that make up the refrigeration system. The illustrated unit 14 is electrically powered by an auxiliary alternator (not shown) that converts the mechanical power of the vehicle's engine to electricity, as is understood in the prior art. Powering the unit 14 electrically greatly reduces the size and weight of the unit 14 because no separate diesel engine is required. Additionally, no complicated and bulky system of belts and pulleys is needed to power the other components in the unit 14. Using electric power to run the unit 14 also reduces fuel consumption, noise, and vibration.
The electricity generated by the auxiliary alternator flows through an electrical control box 150 that, among other things, regulates the electric power with an inverter and distributes electricity to the other components housed in the interior space 72. In the illustrated embodiment, the control box is located in the front-left corner of the interior space 72, adjacent the front side 54 of the unit 14. As best seen in
While the specific design of the control box 150 is not critical to the invention, the illustrated control box 150 is sealed and is externally cooled by circulated water coolant. One example of a suitable control box is described in commonly-assigned provisional patent application No. 60/217,990, filed Jul. 13, 2000.
As best seen in
The discharge end of the compressor 158 communicates with a refrigerant routing system 162 that is supported by the frame 70 adjacent the compressor. While the specific design of the refrigerant routing system 162 is not critical to the invention, the illustrated refrigerant routing system 162 is a compact, modular unit having all of the conduits and components mounted on a single platform or bracket 164 (see
The outlet end of the refrigerant routing system 162 communicates with a condenser coil 166 that is also supported by the frame 70 in the interior space 72. Unlike prior-art flat condenser coils, the illustrated condenser coil 166 is substantially U-shaped and includes abase portion 170 adjacent the front side of the frame 70, and first and second arm portions 174 and 178 (see FIG. 4), respectively, that extend toward the rear side of the frame 70. In the illustrated embodiment, the first arm portion 174 substantially divides the interior space 72 into first and second portions 182 and 186, respectively, and the second arm portion is adjacent the right side of the frame 70. Together, the base portion 170 and the arm portions 174 and 178 define a second interior space 190 within the interior space 72.
An air displacement device, in the form of a radial blower 194 having an integral electric motor, is supported by the frame 70 in the second interior space 190. The blower 194 is electrically coupled to the control box 150 and helps move air through the second interior space 190 in order to cause the hot gaseous refrigerant in the condenser coil 166 to cool and return to liquid form. More specifically, air entering the interior space 72 through the air inlet openings 102 and 122 and through the vent portion 138 of the access panel 126 circulates through the condenser coil 166 to cool the hot gaseous refrigerant passing through the condenser coil 166. While not shown, the condenser coil 166 includes fins to facilitate cooling, as is understood by those skilled in the art. As the refrigerant is cooled, the air absorbs heat. In order to maintain the efficiency of the condensation process, the radial blower 194 discharges the heated air through the discharge outlet 90 in the rear of the frame 70.
The U-shaped configuration of the condenser coil 166 provides many advantages. First, the U-shaped condenser coil 166 occupies less distance along the front side of the frame 70, without sacrificing the capacity that would otherwise be achieved using a prior-art flat condenser coil extending across the entire front side of the frame 70. The arm portions 174 and 178 provide the added surface area needed to achieve the desired capacity, yet do so without blocking access to the components housed in the first portion 182 of the interior space 72, from the front side of the frame 70. The U-shaped condenser coil 166 and radial blower 194 arrangement also draws cooling air across the compressor 158, thereby increasing the efficiency of the compressor 158.
The compact configuration of the U-shaped condenser coil 166 also reduces the airflow needed to obtain the desired cooling capacity, which in turn reduces the required operating speed of the radial blower 194. The lower operating speed of the radial blower 194 reduces the overall power consumption as well as the noise and vibration emitted from the unit 14. Additionally, the radial blower 194 is smaller than the large axial fans used in the prior-art, making the undermount temperature control unit 14 more compact.
The radial blower 194 offers yet another advantage over the axial fans used in the prior art. Prior-art axial fans typically discharge air from the rear of the undermount temperature control unit along the entire height of the unit. This often results in large portions of the discharge air being obstructed by portions of the vehicle's frame. The obstructed air discharge reduces the overall capacity of the temperature control unit and increases the amount of dirt, dust, and other road debris that will be blown into and collected in the unit.
With the present invention, as best seen in
As mentioned above, the access panel 126 can be opened to provide access to the majority of the components (all except the radial blower 194) housed within the frame 70. As seen in
To gain access to the compressor 158 and the refrigerant routing system 162, the control box 150 is movable from a first position, where the control box 150 is inside the interior space 72 and positioned for operation of the temperature control unit 14, to a second position, where the control box 150 is at least partially outside the interior space 72 and positioned to grant access the compressor 158 and the refrigerant routing system 162 from the front side 54 of the frame 70.
As seen in
In the illustrated embodiment, each side of the control box 150 includes a plurality of rollers 206 positioned to roll in one of two rail assemblies 210 coupled to the frame 70. The rail and roller system on each side of the control box 150 is substantially mirror images of one another and only one will be described in detail. As best seen in
After the unit 14 has been serviced or cleaned, the operator pivots the control box 150 up to the position shown in phantom lines in
While the illustrated embodiment utilizes the rail and roller system described above, those skilled in the art would understand that the linear movement of the control box 150 could be achieved in other ways. For example, various sliding guide rail systems, rack and pinion systems, or other similar systems could be substituted for the illustrated rail and roller system. It should also be noted that the control box 150 could be pivoted upwardly instead of downwardly to gain access to the interior space 72. However, such upward pivoting would be more difficult due to the illustrated manner in which the access panel 126 is opened, and in light of the added parts that would be required to hold the control box 150 in the upwardly-pivoted position.
Various features of the invention are set forth in the following claims.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US01/09751 | 3/27/2001 | WO | 00 | 9/19/2003 |
Publishing Document | Publishing Date | Country | Kind |
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WO02/07755 | 10/3/2002 | WO | A |
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Number | Date | Country | |
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20040134227 A1 | Jul 2004 | US |