AU2003100831A4 - A Cooling System - Google Patents

Description

Normax Industries Pty Ltd

AUSTRALIA

Patents Act 1990 INNOVATION SPECIFICATION Invention Title: A Cooling System This invention is described in the following statement: A COOLING SYSTEM This invention relates to a cooling system. In particular, the invention relates to a cooling system for cooling and recirculating oil from a gear box, differential or transfer case.

The invention will be described by way of example with reference to cooling and recirculating oil from a gear box. It should be appreciated that this is by way of example only and that the system of the invention may be used to cool and recirculate oil and other fluids from equipment other than gear box differentials or transfer cases.

Gear boxes in heavy vehicles are lubricated with oil that can become particularly hot through sustained and prolonged running of the vehicle to which the gear box is fitted. This can lead to premature failure of the gear box or greatly diminished serviceable life of the gear box.

Heavy vehicles typically have power steering.

The power steering typically is hydraulically driven by a power steering pump.

At high engine speeds fluid flow in excess of that required for operation of the power steering system is allowed to bypass the system and is returned to a reservoir for hydraulic fluid from which the fluid is normally drawn to operate the power steering of the vehicle. Thus, the energy in this excess fluid is wasted.

SUMMARY OF THE INVENTION According to one aspect the invention provides a system for cooling and recirculating fluid from an apparatus, the system including an hydraulic motor operable to drive an hydraulic pump to draw fluid from the apparatus, a radiator coupled to the pump for receiving the fluid and for returning the fluid to the apparatus whereby excess hydraulic fluid from a pump of a power steering apparatus of a vehicle is employed to drive the hydraulic motor of the system.

The system may have an auto start valve associated with the motor which functions to divert fluid under pressure to bypass the motor until the pressure of the excess fluid from the pump of the power steering apparatus exceeds a predetermined pressure.

The system may also include a relief valve adapted to cause fluid under pressure to bypass the motor in the event of a fluid line rupture.

A relief valve may also be present and function to divert fluid to bypass the pump of the system.

The system may include a suction inlet case assembly adapted to be coupled to a filling inlet of the apparatus. The inlet case assembly allows fluid to be withdrawn from the apparatus through the filler inlet of the apparatus.

A particular preferred embodiment of the invention will now be described by way of example with reference to the drawings in which: Figure 1 shows a preferred embodiment of an hydraulic circuit incorporating the system of the invention; Figure 2 is a perspective of a suction case assembly used with the system of the invention; and, Figure 3 is a sectional view of the suction case assembly of Figure 2.

Figure 1 shows a preferred embodiment of an hydraulic circuit 10 incorporating the system 11 of an embodiment of the invention.

Reservoir 12 contains hydraulic fluid for operating power steering of a vehicle. The reservoir has a filter 13 and a breather port 14. A level sight gauge is shown as part of the reservoir 12.

A pump 16 which forms part of the power steering of the vehicle draws fluid from the reservoir 12 and directs that fluid to a steering box of the power steering. Relief valve 17 normally would function to direct excess fluid under pressure at high revolution speed of the engine which forms part of the vehicle to which the power steering is fitted. This excess fluid would normally be returned to the reservoir via filter 13.

However, as shown, valve 17 directs the excess fluid to the system 11 of the invention. Valve 18 is a pressure relief valve which, in the case of improper operation, returns hydraulic fluid to the reservoir 12.

Figure 1 shows an apparatus 20 which contains lubricating fluid. The apparatus 20 may be a gear box, transfer case or differential or any other apparatus normally supplied with lubricating fluid. Apparatus has a breather port 21, an outlet 22 in communication with a filter 23 and a return 24.

An hydraulic motor 30 receives excess fluid from pump 16 and is driven by this excess fluid. Motor in turn drives an hydraulic pump 31 which draws fluid from apparatus 20. Pump 31 directs the fluid through filter 32 and through a radiator 33. Radiator 33 allows the fluid to be cooled prior to the fluid being returned to the apparatus Radiator 33 has a fan 34. A bypass check valve is connected across the filter 32.

Motor 30 has an auto-start valve 36 connected across it which functions to divert fluid to bypass the motor 30 until the fluid at the inlet of the motor 30 is at a sufficiently high pressure to effectively operate the motor 30. Relief valve 37 is coupled across the auto start valve 36 and a relief valve 38 is coupled across pump 31.

The apparatus 20 may be a transfer case or gear box of the like. It is important that the suction outlet 22 is not placed at a location where it is prone to damage. For example the transfer case or gear box typically has a sump plug which may be opened to drain fluid from the apparatus. It would be undesirable to have the suction outlet projecting into the drain outlet normally closed by a sump plug. If the suction outlet were at that location and was damaged the fluid may escape from the apparatus leading to failure of the apparatus.

The suction outlet may be provided by an aperture extending into a side of the apparatus.

Typically, gear boxes and transfer cases have filler ports normally closed off by a plug. These ports normally extend through the side of the transfer case or gear box. The suction case assembly 40 of figures 2 and 3 may be fitted to the filler port and not only provides the suction outlet required for the system of the invention, but also provides a filling inlet and level gauge or dipstick.

The suction case assembly 40 has a suction nozzle 41 and a body 42. Nozzle 41 normally projects into the gear box or transfer case and is preferably made from sacrificial material which readily is worn away should the nozzle 41 inadvertently contact moving components within the gear box or transfer case. The nozzle may for example be made of aluminium. The assembly has a filler plug 43 which may be unscrewed from the body 42 to allow fluid to be introduced into the gear box or transfer case fitted with the assembly 40. A dipstick assembly having a knob 44 is received by the body and may be screw threaded to the body 42. Suction outlet 45 communicates with the interior of the body 42 and with the interior of the gear box or transfer case via nozzle 41.

Figure 3 shows a sectional view of the assembly of figure 2. The dipstick assembly 44 has a cap 46 screw threaded to the body 42. A seal 47 extends between the cap 46 and the body 42. A dipstick 48 extends from the cap 46 and projects into the nozzle 41. A seal 49 extends between the plug 43 and the body 42. An oil strainer 50 extends around an upper end of the dipstick 48 and any oil drawn through the nozzle and out through suction outlet 45 must pass through the strainer 50. A 6 magnet 51 is located within the body and functions to capture small magnetic particles within the fluid.

A retainer plate 52 is located between the body 42 and a base flange assembly 53. A seal 54 extends between the assembly 53 and the plate 52. Screw fasteners 55 attach the assembly 53 to the body 42.

Spigot 56 is normally thread to allow it to be screw threaded relative to the gear box or transfer case.

Claims (5)

1. A system for cooling and recirculating fluid from an apparatus, the system including an hydraulic motor operable to drive an hydraulic pump to draw fluid from the apparatus, a radiator coupled to the pump for receiving the fluid and for returning the fluid to the apparatus whereby excess fluid from a pump of a power steering apparatus of a vehicle is employed to drive the hydraulic motor.

2. The system of claim 1 including an auto start valve coupled to extend across the hydraulic motor to divert fluid from the power steering pump around the motor until the fluid reaches a predetermined pressure.

3. The system of claim 1 or 2 including a relief valve for diverting fluid to bypass the motor in the event of build up of high fluid pressure at the motor.

4. The system of any one of claims 1 to 3 including a relief valve for diverting fluid around the pump of the system.

5. The system of any one of claims 1 to 4 including a suction case assembly for connection to a filling inlet of the apparatus, the suction case assembly having a suction inlet nozzle for communicating with the interior of the apparatus, a suction outlet for connection to the pump of the system, a filler inlet normally closed by a plug and cap with a dipstick assembly extending therefrom with a dipstick projecting from the cap and into the nozzle. Dated this 2 nd Day of October 2003 Normax Industries Pty Ltd By their Patent Attorneys CULLEN CO.