|Publication number||US3659567 A|
|Publication date||May 2, 1972|
|Filing date||Jul 13, 1970|
|Priority date||Jul 15, 1969|
|Publication number||US 3659567 A, US 3659567A, US-A-3659567, US3659567 A, US3659567A|
|Inventors||Murray Frederick R|
|Original Assignee||Rolls Royce|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (2), Referenced by (24), Classifications (10), Legal Events (2)|
|External Links: USPTO, USPTO Assignment, Espacenet|
0 United States Patent [151 3,659,567
Murray [4 May 2, 1972  DRIVE MEANS FOR THE COOLING FAN OF AN INTERNAL COMBUSTION  References Cited ENGINE UNITED STATES PATENTS Invenwfl Frederick Murray, Namwich. England 2,777,287 1/1957 Tweedale ..123/41.49 x Assigneez Rolls Royce Limited y England 1 Mayr l l  Filed: July 13, 1970 Primary Examiner-Al Lawrence Smith pp No: 54,123 Attorney-Cushman, Darby & Cushman [5 7] ABSTRACT Foreign Applicafiml Priority Data A hydraulic drive for the fan of an internal combustion engine in which an existing constant flow supply of hydraulic fluid is July 15, 1969 Great Britain ..35,551/69 used to actuate a hydraulic motor to drive the fan. A system of valves is provided to safeguard the operation of the primary  US. Cl ..l23/41.12, l23/4l.49 location ofuse ofthe hydraulic fluid  lnt.Cl ..F0lp7/02,F0lp 7/14,F0lp7/16  Field of Search... ..l23/41.l1,4l.12,41.49 2Claims,3Drawing Figures r L I rti f '2 i l 24 I4 Pump L 25 I' L I Moror for Power Steering Mechanism Patented May 2, 1972 2 Sheets-Shoot l NOE floenlor if @516 66 Zjfmeem 4/7- .A/EYS Patented May 2, 1972 3,659,567
2. Sheets-Sheet 2 DRIVE MEANS FOR THE COOLING FAN OF AN INTERNAL COMBUSTION ENGINE This invention relates to drive means for the cooling fan of an internal combustion engine.
It has been a common expedient to drive the cooling fan of an internal combustion engine direct from the output or intermediate stage of the output of the engine itself. This is recognised to introduce various deficiencies. Thus, when the engine requires most cooling, normally at idling speed, the fan is turning at a slow speed and consequently cooling may be marginal; on the other hand when the engine is operating at high speed, although it requires relatively little cooling the fan is rotating at high speed and consequently absorbing an unnecessarily large amount of power.
Previous attempts to solve this problem have involved slipping clutches or similar devices to slow the fan at high engine speeds, or alternatively separate electrical drive means for the fan.
The present invention provides a way in which the fan may be driven hydraulically from what may be an already existing hydraulic power source.
According to the present invention drive means for the cooling fan of an internal combustion engine comprises a hydraulic pump adapted to be driven by the engine and to provide a substantially constant flow of hydraulic fluid, a primary duct adapted to convey the fluid to a primary location for use, a hydraulic fan motor connected to drive the fan, and a secondary duct adapted to convey the hydraulic fluid from the pump to the fan motor.
Preferably valve means are provided, adapted to regulate the flow of fluid to the motor in accordance with the temperature of the engine, thus these valve means may comprise bypass passage around the fan motor which is opened or closed in accordance with engine temperature.
In a particular instance, the primary location of use comprises the power steering mechanism of a vehicle which is propelled by the internal combustion engine.
The invention will now be particularly described, merely by way of example, with reference to the accompanying drawings in which:
FIG. 1 is a diagrammatic view of a motor vehicle incorporating a cooling fan drive in accordance with the invention.
FIG. 2 is a diagram of the hydraulic circuit of the drive of the present invention, and
FIG. 3 shows the valving arrangement of the circuit of FIG. 2 in sectional view.
FIG. 1 shows a motor car which is propelled by an internal combustion engine 11 (shown in broken lines). The engine 11 is arranged to drive, by means not shown, a constant flow output hydraulic pump 12. It will be appreciated that although the pump is referred to as having a constant flow output, it will not in fact be precisely constant; but substantially constant over the normal speed range of the drive from the engine.
Output from the pump 12 is taken by hydraulic pipes and a valve system not shown in FIG. 1, to a first hydraulic motor 13 which actuates the power steering mechanism of the car, and to a second hydraulic motor 14 which drives the cooling fan of the engine.
FIG. 2 shows in more detail the hydraulic circuit of the drive for the motors 13 and 14. The output from the pump 12 passes through an output pipe 15, through a by-pass/relief valve 16, and by way of a pipe 17 to the fan motor 14. Fluid leaving the fan motor 14 exhausts through pipe 18 to the steering motor 13, and finally exhausts from there to return to the pump 12 via a pipe 21.
A by-pass passage 22 is provided which extends from the motor 13; to effect this a pipe 28 taps the pressure downstream of the motor 13 to the valve 25, while the pipes 26 and 22 act as pressure tappings for the upstream side of the motor 13.
In FIG. 3 the detailed construction of the valves 16 and 25 may be seen. The valve 16 comprises a body portion 30 within which operate a relief valve spool 31 and a thermostatically operated valve spool 32. The relief valve 31 is spring loaded by a compression spring 33 against a face of the body 30; it will be appreciated that should the back pressure across the fan motor 14 rise above a predetermined value, this pressure will overcome the spring pressure and allow flow through the by-passage.
The spool 32 seats against the upper extremity of a central hole through the spool 31, and is itself caused to take up an axial position in dependence upon the balance of forces between a compression spring 34 and a solenoid 35 operated by a signal which depends upon the temperature of the cooling fluid of the engine 11. Should the temperature of the engine fall below a predetermined value, the solenoid 35 will allow the spring 34 to push the spool 32 ofl the face of the spool 31 and to allow the hydraulic fluid to by-pass the motor 14, hence slowing or stopping the fan.
The valve 25 is provided to enable the steering motor 13 to take priority in the use of the output of the pump 12. Thus the valve 25 comprises a body 36 within which operates a piston 37, spring loaded by a compression spring 38. The piston is supplied, on opposite faces, with pressures from upstream and downstream of the motor 13 by way of the pipes 22 and 26 and the pipe 28 respectively. From the piston 37 is carried an obturating valve 39 which may open or close the further bypass passage 24. It is arranged that in the normal state of affairs, the pressure difference across the motor 13 and consequently across the piston 37 is such as to cause the valve 39 to close the by-pass passage 24 and consequently to enable the fan motor 14 to drive the fan (always provided that the bypass passage through the valve 16 is closed). Should a predetermined heavy demand be made upon the steering motor, the pressure across it will rise, consequently the valve 39 will open to open the by-pass passage 24 and allow the motor 13 to take the whole flow of the pump 12.
It will be appreciated that the system described allows the fan to be driven at substantially constant speed regardless of engine speed. The thermostatic valve enables the fan to be controlled in dependence upon the temperature of the coolant of the engine, while the relief valve ensures that should the fan motor seize, there will still be power available for the steering motor. Again, the valve 25 allows the steering motor to have priority over the fan motor for conditions where the steering motor is under load.
Various modifications could be made to the device described. Thus the fan could be driven from the output of a separate constant flow pump or by a pump adjusted for other uses. Again, the valve arrangement could well be altered. Also, the thermostat could be a wax thermostat arranged to drive the spool 32 direct.
Again it will be appreciated that the present invention enables the fan to be located remote from the engines, e.g., in front of the radiator matrix.
1. Drive means for the cooling fan of an internal combustion engine of a vehicle having a power steering mechanism comprising a hydraulic pump having a substantially constant output flow of hydraulic fluid, a hydraulic motor having an inlet and outlet for driving said fan, a hydraulic motor having an inlet and outlet for said power steering mechanism, a first fluid duct connecting said output of said pump to said inlet of said fan motor, a second fluid duct connecting said outlet of said fan motor to said inlet of said motor for said steering mechanism, a third fluid duct connecting said outlet of said steering mechanisms motor to said hydraulic pump, a first bypass duct for conveying fluid from said first duct to said second duct, said first by-pass duct having valve means therein pressure at said outlet thereof by a predetermined value.
2. The drive means as claimed in claim 1 wherein said valve means in said first by-pass duct includes a first valve which is controlled by said temperature responsive control means and a second valve which opens said first by'pass duct when the back pressure across said fan motor exceeds a predetermined value.
l '0' I t Il
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US2777287 *||Feb 24, 1953||Jan 15, 1957||Vickers Inc||Motor-pump drive for vehicle fan|
|US3217697 *||Jul 27, 1964||Nov 16, 1965||Sueddeutsche Kuehler Behr||Thermostatically controlled valve|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US3911877 *||Jun 28, 1973||Oct 14, 1975||Dotsch Arnold||Dividing cutting machine|
|US4066047 *||Apr 19, 1976||Jan 3, 1978||International Harvester Company||Toroidal heat exchanger having a hydraulic fan drive motor|
|US4179888 *||May 18, 1978||Dec 25, 1979||Eaton Corporation||Hydraulic fan drive system|
|US4189919 *||Dec 6, 1978||Feb 26, 1980||Eaton Corporation||Motor-valve apparatus for hydraulic fan drive system|
|US4223646 *||Feb 16, 1978||Sep 23, 1980||Trw Inc.||Hydraulic fan drive system|
|US4383502 *||Jan 26, 1981||May 17, 1983||Hans List||Water-cooled internal combustion engine using hydraulic-oil lubrication and cooling-water pump|
|US4446697 *||Dec 4, 1979||May 8, 1984||Eaton Corporation||Hydraulic fan drive system including variable displacement pump|
|US4738330 *||Mar 20, 1986||Apr 19, 1988||Nippondenso Co., Ltd.||Hydraulic drive system for use with vehicle power steering pump|
|US4941437 *||Jun 21, 1988||Jul 17, 1990||Nippondenso Co., Ltd.||Automotive radiator cooling system|
|US5216983 *||Oct 26, 1992||Jun 8, 1993||Harvard Industries, Inc.||Vehicle hydraulic cooling fan system|
|US5501184 *||Dec 8, 1994||Mar 26, 1996||Volkswagen Ag||Motor vehicle having a common liquid supply for a liquid-cooled drive engine and hydraulic power steering|
|US5586871 *||Jun 7, 1995||Dec 24, 1996||Itt Automotive Electrical Systems, Inc.||Electric motor driven fan with water baffle|
|US5685697 *||Aug 2, 1995||Nov 11, 1997||Itt Automotive Electrical Systems, Inc.||Combined check valve and pressure sensor|
|US5960748 *||May 2, 1997||Oct 5, 1999||Valeo, Inc.||Vehicle hydraulic component support and cooling system|
|US5975233 *||Dec 14, 1994||Nov 2, 1999||Mannesmann Rexroth Ag||Hydraulic system for a motor vehicle|
|US6142110 *||Jan 21, 1999||Nov 7, 2000||Caterpillar Inc.||Engine having hydraulic and fan drive systems using a single high pressure pump|
|US6234270||Jan 21, 1999||May 22, 2001||Caterpillar Inc.||Vehicle having hydraulic and power steering systems using a single high pressure pump|
|US6308665||Aug 27, 1999||Oct 30, 2001||Valeo, Inc.||Vehicle hydraulic component support and cooling system|
|US6314729||Jul 21, 1999||Nov 13, 2001||Sauer-Danfoss Inc.||Hydraulic fan drive system having a non-dedicated flow source|
|US6742503 *||Sep 18, 2002||Jun 1, 2004||Caterpillar Inc.||Dual pressure fluid system and method of use|
|US6848255||Dec 18, 2002||Feb 1, 2005||Caterpillar Inc||Hydraulic fan drive system|
|EP0079829A1 *||Nov 10, 1982||May 25, 1983||Roger Clemente||Hydraulically operated fan assembly for a heat exchanger|
|WO1979001084A1 *||Apr 30, 1979||Dec 13, 1979||Eaton Corp||Hydraulic fan drive system|
|WO1980001191A1 *||Sep 20, 1979||Jun 12, 1980||Eaton Corp||Motor-valve apparatus for hydraulic fan drive system|
|U.S. Classification||123/41.12, 123/41.49|
|International Classification||F01P7/04, F01P5/02, F01P5/04, F01P7/00|
|Cooperative Classification||F01P7/04, F01P5/04|
|European Classification||F01P5/04, F01P7/04|
|Feb 2, 1988||AS01||Change of name|
Owner name: ROLLS-ROYCE MOTOR CARS LIMITED
Effective date: 19701028
Owner name: ROLLS-ROYCE MOTORS LIMITED
|Feb 2, 1988||AS||Assignment|
Owner name: ROLLS-ROYCE MOTOR CARS LIMITED
Free format text: CHANGE OF NAME;ASSIGNOR:ROLLS-ROYCE MOTORS LIMITED;REEL/FRAME:004828/0662
Effective date: 19701028
Owner name: ROLLS-ROYCE MOTOR CARS LIMITED,STATELESS