Patent Application
20150369114
The present disclosure relates to a cooling system for a vehicle.
Operating a motor vehicle, such as an agricultural tractor, produces heat that must be rejected to the air through heat exchangers. A typical tractor cooling package will include a fan, a radiator, a charge air cooler, a hydraulic oil cooler, a condenser, and a fuel cooler. There have been many front cooling package designs for tractors all seeking to efficiently remove heat from the tractor. Typically, a fan is used to pull air through fluid filled heat exchangers. This fan is a major consumer of engine power. It is desired to provide an optimal cooling package taking into account space, airflow, and fan power consumed for a variety of loads. It is also desired to provide a practically efficient cooling package based upon the load cases most common to the actual users of the tractor.
U.S. Pat. No. 8,505,499 issued to Hirasawa, et al. on Aug. 13, 2013 discloses a cooling system for construction machine. In this cooling system, a radiator and an oil cooler are arranged at a front surface side of a cooling fan in parallel with each other in a flow direction of the cooling air. An intercooler or charge air cooler and a condenser are arranged in parallel at a front surface side of the radiator and oil cooler, and a fuel cooler is arranged at a front surface side of the condenser. However, the oil cooler is a single pass oil cooler, rather than dual pass. Also, an upper portion of the inter-cooler (or charge air cooler) completely covers or obscures an upstream side of the oil cooler. Thus, the oil cooler receives air that is already warmed by the inter-cooler. This drives a substantial amount of heat into the oil cooler and requires a larger oil cooler, increases the overall size of the entire cooling assembly and requires more fan power. It is desired to have a smaller oil cooler which is exposed to cooling air which has not previously passed through any other cooling unit.
According to an aspect of the present disclosure, a vehicle cooling system includes a fan, a radiator upstream of the fan and in a first air flow path, a charge air cooler upstream of the radiator in the first air flow path, a fuel cooler upstream of the radiator in the first air flow path and adjacent to a side of the charge air cooler, and a hydraulic oil cooler adjacent to a side of the radiator and upstream of the fan and in a second air flow path which is parallel to the first air flow path. The cooling system may also include a condenser positioned in the first air flow path between the fuel cooler and the radiator. The cooling condenser is positioned adjacent to a bottom side of the charge air cooler and upstream of the radiator. The hydraulic oil cooler has an upstream side which is unobscured by any other cooling system components. The hydraulic oil cooler may include first and second hydraulic oil cooler units connected together in series. A portion of the first hydraulic oil cooler unit is positioned above a top side of the charge air cooler, and the second hydraulic oil cooler unit is positioned above a top side of the radiator. At least a portion of the hydraulic oil cooler is positioned above a top side of the radiator. The hydraulic oil cooler is exposed to cooling air which has not previously passed through any other cooling unit.
Referring to
The hydraulic oil cooler 22 preferably is a dual pass cooler which includes a first upstream hydraulic oil cooler unit 24 and a second downstream hydraulic oil cooler unit 26. Units 24 and 26 are connected together in series with respect to the flow of coolant (not shown). As best seen in
Preferably, oil first enters the rear unit 26 (unit 26 is the last or downstream unit of cooler 22 in the second air flow). Then, the oil flows down to a tank and up into the front unit 24 (unit 24 is the first or upstream unit of cooler 22 in the second air flow path). Alternatively, the oil doesn't have to flow down then up—it can flow side to side, or up then down.
The cooling system 10 may also include a condenser 32 which is preferably positioned in the first air flow path between the fuel cooler 18 and the radiator 14. The condenser 26 is preferably positioned adjacent to the bottom side 20 of the charge air cooler 16.
The oil cooler 22 is placed so it is directly exposed to cooling air with no cooler in front of it and no cooler behind, so that the size of the oil cooler can be reduced. Placing the charge air cooler in front of the radiator caused the radiator to have to be larger, but the overall package remained relatively compact and low in airflow. The condenser and fuel cooler can be placed either in front of the radiator or in front of the charge air cooler. Due to the compact arrangement of the heat exchangers in combination with the use of a weighted usage profile, fan power consumption is reduced. It is believed that a shuttered or louvered airflow path for the oil cooler would further reduce the fan power required as air would only be pulled through as much of the oil cooler as required to keep the oil below a specified temperature. Less airflow means less power consumed by the fan or equivalently, better fuel economy.
While the disclosure has been illustrated and described in detail in the drawings and foregoing description, such illustration and description is to be considered as exemplary and not restrictive in character, it being understood that illustrative embodiments have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected. For example, a similar system could be turned upside down where the oil cooler was on bottom, or a similar system could be rotated at any angle. A similar system could be provided with a remote mounted condenser (absent from the cooling package in front of the machine). A similar system could be provided without a charge air cooler, where air-to-coolant methods are used to cool the charge air. A similar system could be provided where the condenser, charge air cooler and fuel cooler can be any combination of present/absent and series/parallel in the first air stream in front of the radiator. Or, a similar system could have with independent fans for the two air streams. It will be noted that alternative embodiments of the present disclosure may not include all of the features described yet still benefit from at least some of the advantages of such features. Those of ordinary skill in the art may readily devise their own implementations that incorporate one or more of the features of the present disclosure and fall within the spirit and scope of the present invention as defined by the appended claims.
