JP4285819B2 - Mechanical cooling system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates generally to cooling systems and, more particularly, to cooling systems that reduce the temperature of oil in an axle assembly or reduce the temperature of engine coolant depending on the operating mode of the machine.
[0002]
[Prior art]
In the operation of a construction machine, it is common for the machine to be exposed to several different working modes. For example, a wheel loader involves loading on a truck, transporting luggage, and other more specialized operations.
[0003]
For example, in the work of transporting a load, since the load is transported from one place to another, there is a large amount of machine movement in which the machine moves at a relatively high speed.
[0004]
Since the braking action has to achieve these high speeds before bringing the machine to a stop, the application of brakes to the front and rear axles is very demanding. When applied, the brakes often heat the oil in the axle housing in which the brakes and brakes are located to high temperatures.
[0005]
There is no problem with axle temperature because the brakes are not so often used when the work equipment is used frequently without being loaded onto the truck or the machine is traveling. However, in these cases, augmenting the engine cooling system is very effective to prevent the engine temperature from overheating.
[0006]
In both cases described above, heat is a byproduct of different operations and is known to cause excessive wear and premature damage to many parts. Several measures are known to be very effective for engine overheating.
[0007]
These measures include expanding the capacity of the cooling system or adding refrigerant into the cooling system. With respect to overheating of the axle assembly, several methods are known for reducing the heat. Some systems circulate oil through an air-to-oil cooler in the axle housing or circulate coolant through the oil in the axle housing.
[0008]
While these systems are known to be somewhat effective, they are often relatively complex and require a number of extra components to achieve the desired result. In addition, these systems are always in operation and are very limited in versatility.
[0009]
Accordingly, it is an object of the present invention to provide a cooling system for a machine that overcomes the problems of the prior art described above.
[0010]
DISCLOSURE OF THE INVENTION
In one aspect of the invention, a cooling system for a machine is provided. The cooling system includes an engine associated with the machine and a first cooling system adapted to cool the coolant (coolant) circulating in the engine. A heat exchanger is disposed in the first cooling system, and engine coolant circulates through the heat exchanger.
[0011]
At least one axle assembly is attached to the machine and a second cooling system is provided for circulating oil through the axle assembly and the heat exchanger.
[0012]
A pump adapted for selectively circulating oil in the second cooling system and drivingly engaging the engine is disposed in the second cooling system. A clutch member is disposed between the pump and the engine for selectively engaging the drive between the pump and the engine.
[0013]
A first sensor for detecting engine temperature is adapted to engage the engine. The first sensor is operatively connected to the clutch member to engage the clutch when the temperature of the engine reaches a predetermined temperature.
[0014]
A second sensor is adapted to engage the axle to detect axle temperature. When the axle temperature reaches a predetermined temperature, the second sensor is operatively connected to the clutch member to engage the clutch.
[0015]
In another aspect of the present invention, a machine including an engine, a pair of axles drivingly coupled to the engine to provide dynamic power to the machine, and a cooling system that reduces the operating temperature of the engine. Improvements are provided.
[0016]
The machine improvement includes a heat exchanger located in the engine cooling system and a second cooling system that circulates oil through one of the axle assemblies and the heat exchanger.
[0017]
A third cooling system is provided that circulates oil through other axle assemblies and heat exchangers. Means are provided for selectively circulating oil through each axle and heat exchanger.
[0018]
Means for detecting the temperature of the engine and axle assembly are also provided. In response to the temperature of either the engine or the axle reaching a predetermined temperature, the detection means activates the circulation means.
[0019]
In the cooling system described above, a pair of sensors are associated with one or both axle assemblies and engine coolant in the engine cooling system. When the temperature of the axle assembly or engine coolant reaches a predetermined temperature, the pump is activated to circulate fluid through the axle assembly through a heat exchanger located in the engine cooling system.
[0020]
If the axle oil temperature is excessive, engine coolant will pass through the heat exchanger to reduce the axle oil temperature. Conversely, if the engine coolant temperature is too high, cold axle oil circulates through the heat exchanger to reduce the engine coolant temperature. Thus configured, the cooling system of the present invention provides the required cooling depending on the operating mode of the machine.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Referring to the drawings, a cooling system 10 for a machine is shown. The machine (not shown) includes an engine 12 operatively connected to a pair of axle assemblies 14, 16 in a conventional manner not shown here.
[0022]
Engine 12 has a conventional structure with an internal cooling system of conventional design. The engine cooling system 18 includes a radiator 20 connected to the engine 12 by upper and lower radiator hoses 22 and 24 and providing cooling of the engine coolant in a conventional manner.
[0023]
A line 26 through which engine coolant circulates is added to the engine cooling system, and line 26 is shown exiting the engine from outlet port 28 and communicating fluid to heat exchanger 30.
[0024]
Another line 32 is connected between the heat exchanger 30 and the engine inlet port 34 to reincorporate engine coolant into the engine cooling system. The heat exchanger 30 is arranged in communication with the pipelines 26 and 32 so that the engine coolant is circulated by a pump 36 driven by the engine.
[0025]
The first axle assembly 14 has a conventional structure having a differential assembly and a pair of axle shafts that extend on both sides and drive a pair of wheels in a conventional manner.
[0026]
A plurality of brake assemblies are coupled to the axle shaft to provide mechanical braking action in a conventional manner. All of these parts are housed in a common axle housing 38 and the individual parts are not shown.
[0027]
The first axle assembly 14 includes a second cooling system indicated at 40. The second cooling system 40 includes a conduit 42 that extends from an outlet port 44 in the lower portion of the axle housing 38 and communicates oil in the axle housing to the pump 46.
[0028]
Another line 48 communicates oil from the pump 46 to the heat exchanger 30. Oil from the heat exchanger 30 is returned to the axle housing via lines 50 and 52 and enters the axle housing through a pair of inlet ports 54 and 56.
[0029]
The second axle assembly 16 is substantially identical to the first axle assembly 14. The second axle assembly 16 includes a third cooling system indicated at 58.
[0030]
The third cooling system 58 extends from an outlet port 62 located in the lower portion of the axle housing 64 and includes a conduit 60 that communicates oil in the axle housing 64 to the pump 46.
[0031]
Another line 66 communicates oil from the pump 46 to the heat exchanger 30. Oil from the heat exchanger 30 is returned to the axle housing 64 via lines 68 and 70 and enters the axle housing 64 through two inlet ports 72 and 74.
[0032]
Oil from both axle assemblies 14 and 16 is circulated by a common pump 46 through a common heat exchanger 30, but each cooling system has its own cooling system to eliminate the possibility of cross-contamination between the two systems. Note that they are kept separate from each other.
[0033]
The pump 46 is driven by an electric clutch member 76. Clutch member 76 is actuated by one of a pair of sensors 78 and 80.
[0034]
The first sensor 78 is connected to the engine 12 by a probe (not shown) positioned in the engine water jacket to detect the temperature of the engine coolant.
[0035]
This probe is connected to a sensor 78 by a wire 82. When the engine coolant reaches a predetermined temperature, a signal is supplied from the sensor to the electric clutch 76 to drive the pump 46.
[0036]
The second sensor 80 is also a probe-type sensor connected to the first axle 14 and detects the temperature of the oil in the axle assembly. This probe is connected to the sensor by a wire 84.
[0037]
When the oil reaches a predetermined temperature, the second sensor 80 supplies a signal to the electric clutch 76 to drive the pump 46. Note that sensors 78 and 80 operate pump 46 in response to engine coolant or axle oil temperature and operate completely independently of each other.
[0038]
[Industrial applicability]
During operation of a construction machine such as a wheel loader, it is common to operate the machine in one of several modes of operation.
[0039]
In one common mode, the machine is utilized for tasks such as loading on a truck that overuses the engine to operate a large number of work implements without much moving the machine.
[0040]
In this work mode, the temperature of the engine coolant rises. When the temperature of the engine coolant rises to a predetermined temperature, which is about 98 ° C. in this embodiment, the first sensor is activated, the electric clutch 76 is engaged, and the pump 46 is driven by the engine 12.
[0041]
Thereby, the pump 46 circulates the oil in the axle housings 38 and 64 through the heat exchanger 30. Since the machine is operating in a mode that does not move much and does not require much braking, the oil in the axle housing is much cooler than the engine coolant.
[0042]
Since engine coolant and oil from the axle assembly are circulating through the same heat exchanger, the temperature of the engine coolant is reduced. When the temperature of the engine coolant reaches about 95 ° C., the first sensor 78 sends a signal to the clutch to disconnect the drive between the engine and the pump.
[0043]
In other modes of operation, such as cargo transport, the machine is used to transport material from one location to another. During this movement, the machine is usually operated in the high speed range.
[0044]
When the destination is reached, a large amount of brake capacity is required to slow down and stop the machine. Thereby, the oil in each axle housing 38 and 64 is heated by the brake assembly housed in the axle housing.
[0045]
When the temperature of the oil reaches a predetermined temperature, which is about 65 ° C. in this embodiment, the second sensor 80 is activated to engage the electric clutch 76. As described above, the electric clutch 76 transmits the drive of the engine 12 to the pump 46 and circulates the oil in each axle assembly 14 and 16 through the heat exchanger 30.
[0046]
During this mode of operation, the temperature of the engine coolant is lower than the oil in the axle housing, so the temperature of the oil in the axle housing is reduced when circulating through the heat exchanger 30. When the temperature of the oil in the axle housing reaches about 57 ° C., the drive of the pump 46 is disconnected by the clutch 76.
[0047]
The cooling system of the present invention can significantly reduce excessive wear and premature damage of many machine parts by providing additional cooling capacity for both the engine and axle assembly. Furthermore, this additional cooling is achieved automatically depending on the operating state of the machine.
[0048]
Other aspects, objects and benefits of the present invention can be obtained from a study of the accompanying drawings, detailed description of the invention and the claims.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a cooling system for a machine having the principle of the present invention.
[Explanation of symbols]
10 Cooling System 12 Engine 14, 16 Axle Assembly 18 Engine Cooling System 30 Heat Exchanger 36 Pump 40 Second Cooling System 58 Third Cooling System 78, 80 Sensor

Claims (8)

A cooling system for the machine,
An engine operatively coupled to the machine;
A first cooling system adapted to circulate engine coolant through the engine;
A heat exchanger disposed in the first cooling system so that the engine coolant is in communication;
At least one axle assembly attached to the machine;
A second cooling system adapted to circulate oil through the axle assembly and heat exchanger;
A pump disposed in a second cooling system in drive engagement with the engine to selectively circulate oil;
A clutch member disposed between the pump and the engine to selectively establish drive between the pump and the engine;
A first sensor adapted to engage the engine to detect the temperature of the engine and operatively connected to the clutch member to engage the clutch when the engine temperature reaches a predetermined temperature;
A second sensor adapted to engage the axle assembly for detecting the temperature of the axle assembly and operatively connected to the clutch member to engage the clutch when the temperature of the axle assembly reaches a predetermined temperature; ;
A cooling system for a machine, comprising:   A machine cooling as claimed in claim 1, wherein a second axle assembly is attached to the machine, said second axle assembly being in communication with a third cooling system adapted to circulate oil therethrough. system.   The machine cooling system of claim 2, wherein the third cooling system includes a pump for circulating oil through the heat exchanger, the pump being operatively engaged with the engine and the clutch member.   5. The cooling system for a machine according to claim 4, wherein the oil in the third cooling system is circulated through the heat exchanger in a manner that does not communicate with the oil in the second cooling system.   2. The machine cooling system according to claim 1, wherein the heat exchanger is a heat exchanger between oil and water.   6. The cooling system for a machine according to claim 5, wherein a radiator is disposed in the first cooling system, and the radiator has a function of exchanging heat between air and water.   The machine cooling system of claim 1, wherein the axle assembly includes a plurality of brake elements arranged in communication with the second cooling system.   2. The cooling system for a machine according to claim 1, wherein the first sensor detects the temperature of engine coolant in the first cooling system, and the second sensor detects the temperature of oil in the second cooling system.

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