US2696170A

US2696170A - Circulating pump

Info

Publication number: US2696170A
Application number: US249653A
Authority: US
Inventors: Hill Myron Francis
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-10-04
Filing date: 1951-10-04
Publication date: 1954-12-07
Anticipated expiration: 1971-12-07

Description

Dec. 7, 1954 7 2,696,170

CIRCULATING PUMP Filed Oct. 4, 1951 IN VEN TOR.

MYRDNFRANEIS [JILL United States Patent @flice 2, 95,170,, RC L IINQH mi a dsfli l;Wanner?C Application October 4, 195-1 Serial No. {49,653 7- Claims. (CL, 103-42) My invention relates tocirculating pumps forv such water. Circulating systems,'for, example, as that in gas enginedautos withjradiators. -to cause' water heated in the engine cylinder. jackets to, circulatev through the radiators and back again through the said jackets for cooling saidcylinde'rs.

Centrifugal-pumps aloneare. now usedfor this service. When engines are idling, however, adequate circulation fails, and thewater in the radiator. becomescold. As

the engine is started up again, thecold watenfrom the gladiator so chills the cylinder that cracks .occur, ruining The object of my invention is ,a combination centrifugal and displacementpump. foragas engine and its radiator to .keep' the engine cool in both running and idling. The centrifugal pump atoperating enginespeeds, pumps volumes of fiuidwithout. developing excessive pressures in so far asthe radiator, isv concerned, andthe displacement gear at idling engine speeds causes enough circulatlign through the radiator to prevent it. from, getting co High pressure pumps, of the type used in hydraulic pressure or lubricating pumps would burst. the radiators which are of thin metal sections. Instead. my rotors pump only at low pressures. They are r'nountedloosely in the pump casing, toj p'ermit enoughv leakage around them to prevent damagln'gpressures' Loosely is used in a relative sense. Hydraulic pumping gears have from .0003 to. .005." clearance between the side walls and between their. teeth. In my invention, the gears or rotors or. impeller and gear may have'ten. times this amount of. clearance and'sometimes more.-

My rotors will pump water at idling, engine speeds when centrifugal pumps. fail to circulate sufiieient cooling water. O'n theoth'er hand, athigher engine speeds they will 'not develop. damaging, pressures.

Centrifugal auto pumps are. usually. cast with no finish machining ofthe. rotor. My rotors also are. cast, with such tolerances to allow. copious leakage. As. pressure rises with speed of. rotation, due to frictionin the water passageways of the circulating system, the leakage of water increasesthrough the tooth and looseness between the rotors and the casing, reducing the displacement per rotation to. minor proportions. A b'y-pass valve also provides an additional pressure limitation.

My pump employs a one-direction outer rotor having blades to fan the water around, something after the order of centrifugal pumps; the blades having rotor contours on one side of each blade for. continuous contact with cooperating tooth contours on one. side of each tooth of the pinion rotor. Although inclined at 'an angle. not the best for. purely centrifugal action, however, by entering. the spaces between the outer rotor teeth, the pinion or innerv or pinion gear, teeth force a discharge.

The outer rotor or impeller teeth are relatively thin in. cross section to provide, large tooth spaces between them. The back faces of the pinion, teeth, are made as large, as possible by adding tothe. back face toIbetter fill these spaces, thus increasingfdisplacement per revo lution. The path traced by the inner. ends'of the impeller teeth as they pass around the. gear e th uring oth asag n l determin the bac f c th k es f the $54. 3 teeth rel'atiye, to its rotation.

Circulating pumps operate -on water in autos and trucks. Separate chambers for oil have been needed; er plain be r ngs capa le otrunn ng t eve a thou and.

revolutions per minute. The roller bearing shown eliminates the oilchamber, since its rollers do not rub against a cage, but roll against separating rollers which in turn are mounted in a rolling support. Bearings of this type, have had long tests underdry conditions. Sand even has been rolled into powder and blown. out by air circulation. They are self-cleaning. 40,000 R. P. M. have been attained without injurious heat, many times the maximum speed of circulating pumps in auto service.

In the drawings:

Fig. I is a plan view taken on line I I of Fig. IIin the direction of the arrows;

Fig. II is a section taken on line II-II of Fig. I inthe direction of the arrows, the pinion being omitted, and the impeller being shown in full lines;

Fig. III is a section of the casing taken on line IIIIII of Fig. I in the direction of the arrows, the bypass valve being shifted for better showing;

Fig. IV is a section taken on line IVIV of Fig. V in the direction of the arrows;

Fig. V is a part plan and part sectional view showing the bearing details;

Fig. VI is a bottom plan view of the impeller of Fig. II on a reduced scale looking upward from the bottom of the pump; and

Fig. VII is a plan view of the port and shelf system in Fig. I on a reduced scale In Fig. I is shown a casing 1 having a hose connection 2 for the intake side of thepump. Its passage or passageway 3 extends, as shown at 4, to the pump cavity 5. This cavity has two portions, the'intake passage or pas: sageway 3 and the discharge region ti (Fig. III) separated from the intake passagewa'yby thewall 7 extending from the bushing 8 to the outer wall of the casing at 9 (Fig. I) and beyond it to the discharge outlet 10.

The outer rotor consists of a back plate or impeller 11 having arms 12 (Figs. I, II, and VI) with driving teeth 20 with convex driving faces. The impeller 11 is driven by the shaft 14 which is driven by the pulley 15 or by such other power as may be desired. The impeller has enlarged spaces between the blades 12 at13 and between the arms of the impeller at.16, and at substantial speeds can act like a centrifugal pump.

The pinion rotor 17, the displacement rotor, is freely mounted on the shaft 18, its teeth driven by the outer rotor. It may have a bushing l9 of Graphitar, which with the super-finish now attainable on shafts is durable in water for the relatively light load upon it. Between the teeth 20 on the impeller 11 there are wide tooth spaces containing liquid driven around in the casing so that considerable, liquid centrifugal force develops at substantial rotary speed for, displacement purposes. Spaces 13 between the arms 12 of the impeller lll connect the tooth spaces to the intake port or suction area 5.

The impeller teeth may be thin as shown at 20. This provides for wide teeth spaces between the impeller teeth. Because these spaces are so wide, the pinion or inner gear teeth may be thick as indicated at 21. The driving faces of the teeth of the impeller and the driven faces of the inner gear have contours for maintaining continuous fluid tight engagements as disclosed in M. F. Hill et al. Patent No. 2,601,397. The non-driven or opposite faces of the inner gear. may have any shape. They may be flat or concave or convex. But they must be of such shape as not to clash with the inner ends of the teeth of the impeller. The thick teeth shown in the drawings are preferable because they displace more liquid during tooth engagement and particularly at full mesh. This displacement 'by. the gear teeth more than offsets loss of efliciency due to the tilting of the impeller teeth in the wrong direction for the best centrifugal action. Each rotor chamber in the discharge section 6 extends from one tooth contact to the next one. These rotors are for clockwise rotation as a pump and discharge radially outward between the points. of the casing at 23 and 24. The discharge takes place over the wall 7 which is outlined by the solid line 25 and the dotted line 26, This wall is illustrated more clearly in solid lines in Fig. VII on a reduced scale. The outlet 10 may be a hole a cover plate 27 (Fig. III) to fit existing engine Pat n ed, 1s?- 7 9.5.4.

casings or it may be any pipe connection of usual form for convenience of flow. To prevent pressure rising to injurious proportions, a by-pass may be used. A convenient location is in the wall 7, with an aperture communicating with the intake passageway 4, as at 28 Fig. I or 28A, Fig. III. A neoprene valve 29 may be riveted in the wall 7 as indicated, so that the rivet may be engaged by tools outside and inside of the casing as the rivet is headed over. The valve is passed thru the aperture. Pressure of fluid in the discharge area above the wall opens the valve to allow escape. The stiffness of the neoprene determines the maximum pressure and should be suited to the desired action. Any form of valve may be used of course, that shown being a convenient one for mass production at low cost.

When castings are made shrinkage occurs in cooling so that castings are smaller than the original pattern castings. However, by careful design of patterns and molds, rotor shrinkage is taken into account so as to maintain correct tooth relations. If the patterns are made of correct thickness for service then the castings will also be of the correct thickness for service although thinner than the patterns. These shrinkages are taken into consideration in making patterns and in designing of the pump. As the casing is cast according to the same plan it also will shrink in such a way as to maintain the same depth of chamber for the rotors to work in. If the rotors and easing bore dimensions are made with theoretical sizes and the castings are put together without machining, the joint between the cover plate and the casing body would leak. Also the rotors would be tight and unable to turn. A gasket 27a of the requisite thickness provides clearance for the rotors to work in and with additional thickness to provide a by-pass for liquid as pressure rises due to speed, pipe friction and other factors in the cooling system of an auto. The rotors may have plenty of room for operation and too high pressure may be prevented. The same is true if the joint between the cover plate and easing body having machined surfaces. As the gasket is made of soft material on those faces which make contact with the cast surfaces it will seal the joint between the casing and cover. A gasket having a layer of fabric filled in on both sides with rubber or neoprene, or any other similar material, will fill the needs of such a pump, and keep the joint tight.

In order to prevent water in the pump from leaking out around the shaft and into the roller bearing, I prefer to use a form of what is known as the linear seal, which consists of one or more rings 30 of neoprene impregnated, often, with graphite, which hug the shaft 14 and which press against side wall members 30a in the casing and are held to their work by the bore 301; of the casing where the seal is inserted. Water is unable to leak out. There may be as many of these rings as desired. One ring does great service. Two rings guard against any flaws that might develop in manufacture of one. The first ring may rest against the end of the bushing 8, the surface of which is smoothed off, then comes an annular disk or washer and a second linear ring and a second annular disk or washer held in position by a snap ring in a groove 300, all of which are of types well known to the art, and are illustrated in Fig. II. The neoprene rings are usually greased before being installed in order to prevent the shaft from sticking to the rings when dry, when first started. Thereafter there is no danger of sticking.

The shaft 14 may be driven by the belt pulley 15 pinned to the shaft. As the pulley drive sometimes exerts a heavier than usual load upon the shaft bearing, a novel type of roller bearing is employed. As this is primarily a water circulating pump without oil bearings my desire is for a roller bearing for indefinite periods of use, without oil or grease. In my Patent 784,002 was shown and described such a bearing tho its oil-less quality was not then recognized. It provided pure rolling motion. Hundreds of thousands of applications however in shafting and auto service proved that lubrication was not needed.

Bearings made under this patent were the first antifriction bearings commercially adopted by autos. The bearing in this pump has substantially a pure rolling action but by different means. In Fig. IV a section shows a main roller 31 and a separating roller 32.

The separating roller harmonizes the opposing roller surfaces in rolling together. The separating roller has the enlarged ends 33, preferably engaging the ends of the main rollers to keep them parallel, as in the patent. But in the patent the diameters of the ends and bodies of the separators had a proportion equal to that of outer separator supports or retainer caps to the main inner races. This bearing, instead, omits that ratio, since to keep to it may mean new manufacturing tools throughout industry for races and other bearing parts.

By locating the axis of a separator substantially in a plane thru the axes of the two adjoining main rollers as indicated in Fig. V at 33, to prevent radial inward or outward thrust as main rollers press against them, and by trimming the diameters of the ends of the separators to lightly touch, or just clear, the shoulders 35 which have diameters determined by manufacturers of standard roller bearings; and then fitting rings 36 around the outsides of such separator ends, a friction free mounting is attained. The separators, under the influence of centrifugal force, roll in the rings; and the rings, instead of running with the shaft as in my early patent, travel differently, it may be forward or rearward, according to separator diameters, but with a pure rolling action. Centrifugal force causing the separator ends to press outwardly against the rings during rolling, causes the rings to run concentric with the other bearing parts. Any displacement, inward or outward, of a separator causes its ends to touch with a reverse action somewhere upon the shoulders 35, and at once push the separators and rings back into concentric relations. The main rollers 31 cannot thrust the separating rollers in or out radially because the latters axes are substantially maintained in the plane 31a through the adjacent main roller axes. Jamming outward or inward is prevented so that the separators touch the shoulders 35 lightly. The retaining ring 36 can be of light construction as its only function is to keep the small separating rollers in place. The ends 33 of the separators normally clear the shoulders 35 by only a few thousandths of an inch. These members are hardened and even ground to accuracy, and may be mounted to just clear the shoulders 35. A bearing for a shaft of 1% diameter having applicants earlier type would run indefinitely without injurious heat at 40,000 R. P. M.

To prevent the rings from drifting endwise off from the separator ends they may be guided by grooves illustrated at 37. The advantage of this roller system is that it can be applied to many makes of antifriction roller bearings.

Endwise fluid pressure balance is needed to prevent wear between the rotors and casing endwise. The pinion has the same fluid pressures at both ends. The spider is balanced by fluid pressure in the rotor chambers being communicated to the rear side thru the spaces 16.

To provide for any minor residual unbalance, the driving plate runs against the bushing 8 and its shaft carrying the pulley 15 runs against a washer 15a and sleeve 34 of the roller bearing. The sleeve runs against the rollers 31 which run against the inner shoulder 36a on the outer race which is fixed to the pump casing.

It is obvious that my invention may also be used as a motor by causing fluid under pressure to travel thru the mechanism in reverse, causing the rotors to run counter-clockwise. The outgoing shaft 14 then may apply power, thru the pulley or by direct action, to outside use. Nor is it limited to liquids, for gases also may be employed.

My mechanism is designed for one direction operation. As a pump it operates clockwise. If counter-clockwise operation is sought, curves for the opposite sides of the rotor teeth are employed.

Many variations in passageways, valving, sizes, character of curves, with good or inferior tooth engagements, due to imperfections of manufacture or to design, lie within the scope of my invention.

I claim:

1. A rotary fluid mechanism comprising a casing, an intake passage and a discharge passage in the casing, a drive shaft, an impeller mounted on said shaft and in said casing, a pinion gear in said casing within and eccentric to said impeller, a shaft and journal for said pinion gear supported by said casing, said pinion gear having teeth, each of which has an enlarged portion on one side face relative to the other side face, said impeller having teeth relatively thin compared with the thickness of the teeth of the pinion gear in cross section relative to a plane at right angles to the axis of rotation of the impeller and which are so shaped to drive fluid around in said casing to develop centrifugal fluid force to drive fluid out of said discharge passage, one face of said teeth of said impeller having contours for maintaining continuous fluid tight engagement at steady angular speeds with contours on the said other side face of said teeth of said pinion gear, the said enlarged portions of the teeth of said pinion gear each being limited in size and shape to pass the inner ends of the teeth of said impeller during tooth engagement, and said pinion gear acting as a displacement member.

2. A rotary fluid mechanism according to claim 1 in which the enlarged portions of the teeth of the pinion gear and said impeller teeth have more than normal sealing clearance with respect to each other and the casing to provide a fluid passageway between said teeth from the intake passage to said discharge passage to prevent excessive pressure in said discharge passage.

3. A rotary fluid mechanism according to claim 1 in which the teeth of both the impeller and the pinion gear have more than normal sealing clearance to prevent excessive pressure in said discharge passage.

4. A rotary fluid mechanism according to claim 1 in which a wall is provided in the casing to separate the intake and discharge passages, and in which a by-pass valve is provided in said wall to limit the fluid pressure in one passage as compared to that in the other passage.

5. A rotary fluid mechanism according to claim 1 in which a wall is provided in the casing to separate the intake and discharge passages and having an aperture therein, and in which a by-pass valve is provided in said wall to limit the fluid pressure in one passage as compared to that in the other passage, said by-pass valve being in the form of a flap and extending through the aperture, one end of said flap being attached to one side of said wall and when closed, the other end of said flap resting against the other side of said wall.

6. A rotary fluid mechanism according to claim 1 in which the teeth of said pinion gear and said impeller differ in number by more than one.

7. A rotary fluid mechanism according to claim 1 in which the teeth of said pinion gear and said impeller differ in number by two.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,496,222 Hill June 3, 1924 1,513,659 Wardwell Oct. 28, 1924 1,972,355 Peters Sept. 4, 1934 2,011,184 Peters Aug. 13, 1935 2,117,877 Fisher May 17, 1938 2,312,514 Zimmerer Mar. 2, 1943 2,416,987 Fleischer Mar. 4, 1947 2,445,967 Pigott July 27, 1948 FOREIGN PATENTS Number Country Date 370,474 Great Britain Apr. 11, 1932