US2553214A - Temperature control for cooling internal-combustion engines - Google Patents

Description

E. J. SANDERS 2,553,214 TEMPERATURE CONTROL FOR COOLING INTERNAL-COMBUSTION ENGINES May 15, 1951 2 Sheets-Sheet 1 Q\ MR WW E 3 R 9% r/ R m & Q

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E. J. TEMPERATURE CONTROL FOR COOLING INTERNAL-COMBUSTION ENGINES Filed July 21, 1947 2 Sheets-Sheet 2 FIE: E,

Patented May 15, 1951 TEMPERATURE CONTROL FOR COOLING INTERNAL-CQMBUSTION ENGINES Elmore J. Sanders, San Gabriel, Calif., assignor to Evans Products Company, Plymouth, Mich., a corporation of Delaware Application July 21, 1947, Serial No. 762,405

Claims.

This invention relates to temperature control for cooling an internal combustion engine equipped with variable pitch fan blade assemblies which vary the volume of air supplied for cooling purposes, and an object is to produce a simple and eflicient mechanism for supplying fluid under pressure to control the pitch of the fan blades, and thermostatically regulating the effectiveness of the fluid.

Another object is to control the operation of a variable pitch fan used for engine cooling purposes by means of liquid under pressure, such as oil from the engine crank case, and regulate the pressure created by such liquid by thermostatic means responsive, for example, to the temperature of the engine cooling liquid.

These and other objects and advantages of this invention will hereinafter appear, and for purposes of illustration but not of limitation, an embodiment of the invention is shown in the accompanying drawings, in which Figure 1 is a schematic view partially in section of a portion of an internal combustion engine mounting the parts illustrative of the invention; and

Figure 2 is a fragmentary sectional elevational view partially in section of the variable pitch fan blade assembly with a portion of the fan blade adjusting means mounted on the front thereof.

This invention contemplates the use of a mechanism for adjusting the pitch of the fan blades of a variable pitch fan blade assembl of the type described in my United States Patent No. 2,437,810, granted March 16, 1948, and entitled Variable Pitch Fan Blade Assembly. The mechanism includes fan blade pitch controlling means responsive to pressure fluid and separate means regulated in accordance with the engine temperature, such as the temperature of the cooling liquid, to regulate or control the effectiveness of the pressure fluid. Thus, the pitch of the fan blades may be varied in accordance with the temperature of the cooling liquid.

In specific application, positive results have been achieved when the pressure fluid .is hydraulic' fluid circulated at relatively constant pressure by the oil pump of the engine, but suitable fluid pressure may be developed from other sources, such as by the application of atmospheric pressure against the intake manifold vacuum.

Referring now to the drawings, indicates the forward end portion of the motor block of an internal combustion engine having a jacket ll through which cooling liquid l2, such as water, is able to flow. A rotatably mount-ed stub shaft l3 extends forwardly of the motor block and is driven by means of a grooved pulley 14 connected by a belt IE to an engine drive shaft (not shown). Mounted on the end of the shaft [3 is a variable pitch fan blade assembly F constituted generally of a series of fan blades [6 extending radially from a hub portion H.

The variable pitch fan blade assembly F is fully described in my co-pending application previously pointed out, and detailed description thereof is considered unnecessary except as to the manner in which the regulating mechanism cooperates with the fan blade assembly for varying the pitch of the fan blades. Suifice it to say that the fan blade assembly comprises a multiplicity of radially extending fan blades 16 which are counterweighted constantly to urge the fan blades to go into pitch during the operation of the fan. Each of the fan blades carries a stub shaft formed of successive sections of large and small diameter I! and I8 respectively. The shaft section [8 of smaller diameter is mounted between ball bearings is housed within a flanged cup-shaped member 20 that seats in an annularly recessed portion 2| formed in the split sections 22 and 22a that comprise the hub H, which sections are joined together by bolt means (not shown).

Each stub shaft l8 has a depending screwthreaded portion 23 threadably engaged by a 7 jack nut 24 which supports the roller bearing l9. By turning the nut, a depending pin 25 is withdrawn from an aperture 26 through a disc member 2'! rotative in the area between the split hub sections 22 and 22a. When properly assembled, transverse apertures in the pin 25 and the disc 21 are in registry so that a key 28 may be inserted therethrough to maintain the parts in their assembled relation. Each disc 2! carries 4 a pin 29, which is offset from the center of the disc and seats in an aperture 30 formed in the outer or peripheral wall of an actuating sleeve 3|. The rearward wall of the sleeve 3| is formed with an annular groove 32 having a substantially perpendicular outer side wall 22 and a sloping inner side wall 34, while the forward wall of the sleeve is also recessed, as at 35, to provide space in which part of the sleeve actuating means, hereinafter to be described, may be positioned to provide for a more compact unit.

Responsive to the longitudinal movement of the actuating sleeve 3|, the elements described cooperate to effect the rotative adjusting movements of the fan blades in one direction or the other relative to the supporting hub member. Movement of the actuating sleeve in the forward direction is constantly urged by a coil spring 36, which is conically shaped in longitudinal section with the end portion thereof of larger diameter seating within the annular groove 32, While the other smaller end portion of the spring bears against a wall which may form a part of, or is fixed to, the end of the stub shaft I3. Longitudinal movement of the sleeve in the rearward direction may be effected by means of a horizontally disposed shaft 3! having a threaded end portion 33 which mounts a sleeve 39. The sleeve 39 is provided with an annular flange it! at the forward end thereof which engages the forward wall of anti-friction bearings 4| that separate the sleeve 39 from the actuating sleeve 3|. The latter sleeve is provided with an-inwardly extending shoulder 42 for engaging the rearward wall of the bearings '4 Thus relative rotational movement between the actuating sleeve and the shaft 31 is permitted, while longitudinal movement of the shaft 31 provides for corresponding movements of the actuating sleeve.

The shaft 31 is adapted to be shifted in one direction or the other by means of an actuating device A sta'tionarily supported on the front of the hub section H. For purposes of mounting the device, there is provided a bracket in'the form of a disc plate 43 having an outwardly extending annular flange il with a number of apertures therein and a central apertured por- 'tion 45 through which the shaft 31 extends. The bracket '43 is fixed, as by brazing, to the forward open end of a sleeve d6 which is closed at the other'end by a wall 41 having a central aperture through which the shaft 31 slidingly extends. Additional support for the shaft 31 may be provided by an adaptor 28, which is screw- -'threaded on its outer wall threadably -to engage the inner wall of the sleeve '46 in which it is disposed. The adaptor 48 is closed at its forward end by awall 49 having an aperture through which the shaft slidingly extends, and it is provided with a fluid packing to which encases that portion of the shaft 3? that is disposed within the adaptor.

In order to enable relative rotational movement between the hub section I-I andthe bracket 43 and, at the same time, to provide for sulflcient s pport, anti-friction means are interposed between a horizontally disposed sleeve section "52 forming the central part of the hub section 22'and the sleeve 46. The sleeve section 52 has an 'inturned annular flange 53 at the forward end thereof for preventin relative forward'movemerit of the anti-friction means 5|, rearward relative movement thereof being prevented "by means of a "stop nut 54 threadably engaging the t'hrea'ded end portion of the s'leeveA'B. v

The shaft actuating device A is formed of a frigid housing '55, the rearward wall of which is provided with outwardly extending flanges 55 "having apertures therein, which maybe placed in registry with the openings in the flange M. The housing SE-may then be held in this position 'by 'bolt and nut means 51 insertable'through the registered openings. Separating the chamber within'the housing into forward and rearward compartments 58and 59 respectively, is a mov- :able wall, which in'the' preferred embodiment, consists of a vertically disposed diaphragmfi!) of resilient material having the edge portions thereof secured in sealing relation between the housing wall, but may equally be in the form of a piston reciprocal within the chamber. To enable the desired movement of the diaphragm 60, that portion disposed within the housing is adapted to be larger than that of the cross sectional area of the compartment in which it is disposed. As a result, the central portion of the diaphragm is shiftable longitudinally relative to the housing to a limited extent.

Engaging the rearward wall of the diaphragm is a rigid plate '5! secured-to the end of the shaft .31. The plate and shaft is constantly urged in 'the .forward direction by a coil spring 62 interposed between the plate and the rearward housing wall 63 and supplemented by the forces developed by the coil spring 36. These sprin forces supplement the centrifugal torsion developed by the counterweights on the fan blades for causing the fan blades to move into pitch, and they operate alone for such purpose when the speed of the engine is such that sufiicient centrifugal torsion is not made available. Rearward -displacementof the shaft against the forces developed by the coil springs and the counterbalanc'i-ng means results from other forces acting on the opposite face of the diaphragm. For this purpose, use is made of pressure fluid delivered by the fluid pump which forms a part of most engines. The pressure fluid enters and leaves the compartment 58 through the port =56 connected bya tubular passage 65 with the fluid pump. Instead of the coil spring 62, pressure fluid may be used for causing movement of the diaphragm and shaft in the direction to cause the fan blades to go into pitch. In such instances, a coil spring or other biasing or pressure fluid means may be employed in the other chamber for effecting the translatory shifting movement of the diaphragm and shaft in one direction or the other for controlling the pitch of the fan blades.

For regulating the fluid pressure within the chamber, or the flow of fluid to and from the actuating device, there is interposed between the fluid pump and the actuating device A, a pressure fluid regulating means B consisting generally of a by-pass for the liquid under pressure, and valve means responsive to the temperature of the cooling liquid for regulating the flow of liquids through the by-pass. More specifically, the fluid regulating means comprises a cylindrical housin 58 positioned upright on the motor block Hi, the lower end portion of the housing being screw-threaded at 67 for enabling threaded engagement with a threaded aperture 63 through the upper wall 69 of the water jacket H. The

.housing is divided into an upper chamber 10 and alower chamber "H by means of a horizontallydisposed wall l2 having an aperture ?3 through the center thereof. That portion of the wall bounding the upper portion of the aperture "33 is tapered outwardly'at an angle corresponding to the .slope of a frustum shaped valve member 'i' ishiftable vertically-through the opening 13. When the lower portion of the member ii of small cross section is disposed within the opening '13, a relatively large annular space remains about the member'for enabling ready communication between the chambers H and Hi, but when the member is shifted in'the downwarddirection, .the space becomes more restricted until 'comm'unicationbetween the chambers is "entirely out off. This occurs when'the tapered side wall of the frusto-conical member 14 seats in the aperture, with the engaging tapered portions providing for a greater area of engagement. The member 14 is guided in vertical shifting movement by a pin 15 secured to the upper wall thereof and shiftable within a concentric opening H5 in the upper wall of the housing, and by another pin Tl depending from the lower wall thereof and shiftable through an aperture 18 in a bushing 19 that threadably engages a threaded opening Bl! through the lower wall of the housing 66.

Vertical shifting movement is imparted to the pin 1! and consequently the member 54, by means of a thermostat Bl disposed in the fluid stream of a water jacket H. Thermostats of the type to impart vertical shifting movement in response to temperature changes are commercially available, such, for example, as the unit marketed under the designation Vernatherm, and since the thermostat itself forms no port of this invention, detail description thereof is considered unnecessary. Suffice it to say that responsive to increases in the cooling liquid temperature, the frustum member I4 is shifted upwardly, and it is shifted in the opposite direction in response to reductions in the cooling liquid temperature.

Oil or other fluid is delivered under relatively constant pressure from the outlet of a fluid pump (not shown), through a tubular passage 82 to the inlet port 83 forming a part of a side arm passage 84 leading to the chamber H. Interposed between the port 83 and the chamber H is a restriction in the form of an apertured sleeve 85 for reducing the amount of fluid that is able to pass into the chamber H. The fluid by-passed from the lower chamber H into the upper chamber HI through the annular opening about the frustum member 14 is returned to the fluid supply or sump through a side arm passage 86 having an outlet port 8! connected by a tubular passage 88 to the sump (not shown). Another side arm passage 89 leading from the lower chamber H is in communication with the tubular passage 65.

In normal operation, the several fan blades I6 are thrown into a predetermined pitch by the counterbalancing means described. Thereafter the means described function automatically further to increase or to decrease the pitch of the fan blades and correspondingly the volume of the cooling air directed by the fan blades to the radiator or to the engine in accordance with the increase ordecrease of the temperature of the cooling liquid. In this manner, not only is the temperature of the cooling liquid maintained within a narrow temperature range but the power requirements for operating the fan assembly are at a minimum because, when the cooling water is at a low temperature, practically no power is expended in actuating the fan blades.

In normal operation, pressure fluid circulates from the fluid pump into the lower chamber H, thence through the by-pass or aperture l3 and into the upper chamber, from which it is returned to the fluid source. Because of the restriction between the two chambers, a pressure differential between the fluids therein may be made to exist, and the pressure differential may be varied in accordance with the position of the frustoconical member M or valve which regulates the opening between the chambers in the manner described. For example, as the temperature of the cooling liquid decreases, the valve member 54 is shifted downwardly further to restrict the annular space or by-pass opening between the chambers with the result that higher fluid pressures are built up within the lower chamber, and as the temperature of the cooling fluid 12 increases, the thermostat shifts the valve member 14 upwardly to provide for a larger by-pass with a proportionate reduction in pressure.

The pressure in the lower chamber H has a direct affect on the flow of the pressure fluids to the chamber 58. When the fluid pressure therein is increased, as when the member H shifts downwardly further to restrict the opening, pressure fluid flows to the chamber 58, causing the diaphragm 60 and the shaft 31 to shift rearwardly against the forces of the springs and the counterbalance to reduce the pitch of the fan blades. Thus the air flow and concomitantly the power requirements for operating the fan are reduced. When the frustum I4 is shifted upwardly in response to an increase in the temperature of the cooling liquid, the fluid pressure within the the lower chamber is proportionately reduced, and the forces operating to increase the pitch of the fan blades force some of the pressure fluid backinto the circulation with the result that the shaft may be shifted forwardly and the pitch of the fan blades is increased so that a greater volume of air is directed to the radiator or the engine.

A cardinal feature of this invention resides in the association of parts which provides for a simple and constantly operating means for automatically and smoothly varying the pitch of the several fan blades of a variable pitch fan blade assembly in accordance with the temperature of the engine, and although the embodiment of the invention is that of a liquid-cooled engine, the invention is not to be regarded as so limited, because it can advantageously be embodied in an air-cooled engine in which a thermostat may be in metal to metal contact with the cylinder head, for example. In the illustrated embodiment, a fluid, such as oil from the crank case, is circulated under pressure by the usual oil pump and is delivered at substantially constant pressure to a valve means thermostatically controlled from the cooling liquid for regulating the flow of the oil, and a fluid actuated means is provided for effecting the regulation of the pitch of the fan blades responsive to the pressure of the oil. An important concept is the utilization of a fluid for fan pitch controlling purposes, and although oil from the engine crank case is hereby specifically described, it is to be understood that gaseous fluids, such as subatmospheric pressure fluid operating in opposition to gas at atmospheric pressure, may be employed to advantage.

The thermostatically controlled fluid valve may be positioned to function in cooperation with any part of the engine for regulating the pitch of the fan blades in accordance with the temperature of the engine in a specified region. The fan blade actuating means may be positioned any distance from the fluid regulating valve; it may be positioned on the front of the fan assembly and immediately to the'rear of the radiator; it may be positioned on the rear of the fan assembly, which it may actuate, as a result, by means of a pusher rod; or it may be offset from the fan assembly with which it may be operatively connected by means of suitable lever rods. Together the thermostatically controlled valve and the actuating device comprise parts which are simple to manufacture and assemble on a mass production basis and together they form a constantly operating system which requires little repair or '7 adjustment automatically to efiect the desired regulation. 7

It is to :be understood that numerous changes in the details of construction, arrangement and operation of various parts may be effected without departing from the spirit of the invention especially as defined in the appended claims.

What I claim is: 1. In a liquid cooled internal combustion engine equipped with a variable pitch fan blade assembly adapted'to supply air for engine cooling purposes, means responsive to the temperature of the cooling liquid for varying thepitch of the fan blades,

.said'meanscomprising achamber having a movable rwalloperativel-y connected to the fanblade assembly, a source of fluid under pressure, said source and fluid being inherent operatively .to the engine and in communication with said chamber, and means responsive to the tempera- .said source andfluid being inherent operatively to .the engine .and .in communication with said chamber to actuate saidmotorin one direction, .biasing.meansindependent.of said motor to actuate said motor in the other direction, and valve I means thermostatically responsive to the tem perature of the engine for regulating the pressure of the fluid in said chamber to vary the pitch of the fan blades.

3. ,Inan internal combustion .engine equipped 1 with a variable pitch fan blade assembly adapted to supply air for engine cooling purposes, means responsive to the temperature of the engine for varying the pitch of the fan blades, said means comprising a chamber, a diaphragm separating the chamber into two compartments and having a portion thereof movable within the chamber and operatively connected to the fan blade assembly, a source of fluid under pressure, said source and fluid being inherent operatively to 1 the engine and in communication with at least one of said compartments, and valve means responsive to the temperature of the engine for regulating the pressure of the fluid in communication with said compartment and thus varying the pitch of the fan blades.

4. In a liquid cooledinternal combustion engine equipped with a variable pitch Ian blade as.-

sembly adapted to supply air for engine coolin purposes, means responsive .to the temperature of the cooling liquid for varying the pitch of the fan blades, said means comprising an'expansible chamber motor having a movable wall operatively connected to the fan blade assembly for effecting fan blade adjustments, a source of pressure fluid, said source and fluid being inherent operatively to the engine and in communication with said chamber, a valve member regulating the fluid in saidchamber and thermostatic means disposed within the cooling liquid actuating said valve member in accordance with the temperature of the cooling liquid thereby to'vary the pitch of the fan blades.

5. In an internal combustion engine equipped with a variable pitch fan blade assembly adapted to supply air for engine cooling purposes, means responsive to the temperature of the engine for varying the pitch of the fan blades, said means comprising a chamber having .a movable wall operatively connected to the fan blade assembly for effecting fan blade adjustments, a source of pressure fluid in communication with said chamber, a housing interposed between the pressure fluid source and said chamber, a wall ,in said housing having an aperture through which the pressure may be by-passed to the fluid source, a shiftable valve member cooperating with said aperture for regulating .the flow of the pressure fluid through said bypass, and means movable in response to changes in the engine temperature and operatively connected to shift said valve member therebyto vary the flow of pressure fluid through the by-pass-With the result that the pressure or fluid within said chamber is also varied for effecting the desired pitch of the fan blades.

'ELMORE J. SANDERS.

REFERENCES CZETED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,327,381 Fruber Jan. 6, 1920 2,022,709 Embery =-et a1 Dec. 3, 1935 2,231,292 Neugebauer Feb. .11, 1941 2,316,940 Dewey et a1 Apr. .20, 1943 2,354,948 Dewey Aug. 1, 1944 2,392,341 Squier Jan. 8, 1946 2,437,810 Earley etal Mar. 16, 719.48

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