US2746394A - Gear pump - Google Patents

Description

May 22, 1956 J. DoLzA ETAL GEAR (PUMP Filed Aug. ll. 1951 y l/ V SEAL aff d W INVEN TORS M 44M d May 22, 1956 J. DOLZA -rAL 2,746,394

GEAR PUMP Filed Aug. 11, 1951 6 Sheets-Sheet 2 N Xyf jgfaridr .id/ar Jar IN V EN TORS May 22, 1956 J. DoLzA Em. 2,746,394

GEAR PUMP Filed Aug. ll. 1951 5 sheets .sheet 3 fvfvs I l, /r

KY' hun" u 1N VENTORJ fm 7 Mwra May 22, 1956 J. DoLzA ErAl.

GEAR PUMP 6 Sheets-Sheet 4 Filed Aug. 11. 1951 INVENTORS May 22, 1956 J. DoLzA ErAL GEAR PUMP 6 Sheets-Sheet 5 Filed Aug. ll, 1951 INVENTORS May 22, 1956 J. DoLzA ETAL 2,746,394

GEAR PUMP Filed Aug. 11, 1951 e sheets-sheet e k u Q w 52 g u Tof Figui: i

, GEAR PUMP fIohnuDolza, Davisburg, Earl `W. Rohrbacher, Detroit, and

Jo'lm- Zimmerman, 'Grosse Pointe Woods, Mich., as-

signors to General `Motors Corporation, Detroit, vMich., :incorporation of Delaware x Application August 11, 19s1,seria1N0.241,43z

6 claims. (C1. 10s- 126) vThis invention relates togear pumps suitable for use in liquid-pressure systems, for example, .the burner fuel system of aninternalcombustion turbine.

object of the present invention is to .provid-ea `gear vpump of compact and `durable construction capable of pressurizing aliquid to a relatively high pressure ln the disclosed `emlzfodirnent thereof, the object is accomjplishedbysubjecting the gear shafts to forces obtained ,by

pressure fluid which practically balance-out` the 'forces to @which-die shafts are subjected due to gear-tooth `loading andyhydraulic loading `of the pump.` These balancingforces.- areapplied through the usel of pressure pockets adjacent to the shafts.` Each gear shaftihas two` cylin- 'fdfrical `portions .between :which a pump -gear is located. .Eaclfr cylinder lis received `by -a sleeve having `:internal longitudinal. grooves `which `are :separated by .sea-ling` segmentsl whichv litthecylinders with. closeuclearance.. The

pockets-which "these grooves provide `are `connected with thegpump Athat they-receive iuid` under? diderent pressures.

The. elective area of the pockets,it'he` location of the Vipocltets and'theiluid. pressurein-the pocketsua-relsuch that the required balancing eifect isf obtained. `Because the shatt bearings :are-practically free of forces'due to `ge'trftootlr loading; andzhydraulicyloading of theypump, v`they:can-:loe relatively small in diameter land -thepurrrp shafts can ble-'relatively closely Vspaced.. rEheretore a gear pump.' which iscornpact .andduralble inwconstruction ,.andwhich kis capable of pressurizi-ng liquid tozaxrelatively .high pressurefcan be provided. Further objects and advantages ofithepresentrinven- `Fig.` luis-.a longitudinal sectional A'View' on; lineal-1 of Fig. `flA-is an enlarged ragmerrtaryview showing `the ,attaehmentofa pump screen-.toa mounting ring; 1 AFig-...-:1B` is .an `enlarged fragmentaryv viewz-of `.one of f thefshaftseals Fig,` 2 is ay sectional view online 2*-2 of 1*.

` 2,746,394 Fatented May 22, 1956 Figs.' `14 and 15 are respectively, sectional views on ice Figs. 16 and 17 are, respectively, sectional -viewson i lines 16-"16 and' -17-17 of Fig. 14.

lodged from. the. pump.

' Fig. 18 is an enlarged fragmentary, longitudinal sectional view showing a shaft `and a sleeve which vprovides sealing segments between `pressure pockets.

Fig. 19l is a sectional view ron line 19h19 `of Fig.,` 1. Fig. 20 is a sectional viewwon line 20-20 of Fig. 19. Fig. 2'1 is an enlarged end view'. of a drivexshaft pocket sleeve.

Fig. 22isa sectional view on A.line 22-22 of Fig. 21. Fig. `23 .is an end View. of a driven'shait` pocket sleeve. Fig. 24 is a sectional view online 24-.24 of Fig. 23. .Fi-g;l 25 `is a side viewof'the pump. p Referring to Fig. 1, the pump enclosure comprises Ya front bearing housing '30f,na plate 31)?, agear housing'32,

'.:aiaplate Sir-and. arear `bearing housing 301', portions .of

andi-3.9m, respectively. A. ring-44 secured tto housing 30r `retains screen 42. Screen4`0 isretan'med :betweenthe left :flange ofwhousing 39j and the :plate 31j. These screens serve to protect the pump during stonagefandhandling :but arenot reliedupon to iilterthe iluidwhiclr. passes into and out. of .the pump. vThe liquid which/enters the `purnpfis ldltered -by'iforcing it` through-a 40: micron lter by means of an auxiliary pump whichreceives liquid from a` booster gearwpump submerged-in the liquid contained in aisupply reservoir. rEhe liquid dischargedfrom .the disclosed pumpxmay-bedlteredby a `filter rwhiclrwis `capable of retaining metal particles which may be :dis-

. i Housings, 30j and. 301-' support,y respectively,` dri-ve shaft pressure pocket sleeves.v )c and 50r and drivenishaftfpressure pocketlsleeves 51] and 51x. (Fig. l). Sleeve 50f isshownv in Figs.1'2l\and :2.2. on large scale Iands-sleeve f5-1.35 `in Figs. 23 and 24. Each of the housings 30j and ".3017 receivestthepstemb 52 of a disc 53, the periphery. of

which `is received by recesses 54 of the sleeves',` as. shown in; Figs.` 2l=-24. The `disc 53 locatesV the "sleeves 50]? :and

.p Silrjland 51j? and 51ir in certainl angular positions: and pre- Figs. 3 and 4` are, respectively, sectional views on. lines '3e-saudi 4-4ef-rig. 1. l

"Fig, x5' isav fragmentary, sectional'view on linesl 5-5 Figli. 6'- isa fragmentary, sectional.' view on line 6--6 oFigJJ. Y

Figf' is a fragmentary, sectional View on lines'7`-,7

i 'lines'.I-lll and 11-11 ot Fig; 1. -andwl are, respectively, sectionalmviews on 'linesA12--12 and 13-13.of,Fig.: 2..A

vents rotation of these sleeves with respect tothehousings. Y i

` 4Referring to Figs.` 21 and 22.,` sleeve: 501 `is-longitudinally -grooved toprovide4 pockets Af-Bf Cf and Di Referring to Figs. 23 and 24, -sl'eeve` 51f is longitudinally g'rooved toV provide` pockets4 AjQB, Cf and'` Df.. Before these pocketsy arefformed', ftheinterior cylindrical surfaces ofi the sleeves indicated at 55 in Figs. 21E-and: 2'4 and the ,shoulder portions 56 are coated with` a uniform l'ayerz57 ofl babbitt'permanently bonded-tofthesleeves..The grooving of the sleeves to `form these pocketsy leaves babbitt p coated sealing segments. marked Il, .ILfIII andlV. closely .ttingiwitlr cylindrical portions of the` shafts.` `The ends of these pockets are. closed byl ringsfg581 having lalyers` of `babbitt59 bonded ftothe internalcylindrical-.surfaces thereof. The lrings l 58,'are forced into annular recesses providedby the sleeves, f

As shown in Fig. l, sleeves Silf and 50r and 51f .and -51r,f.respective1y, receive a drive shaft 60 'and a; driven shaft A615;,"lheseyshaftst are supportedfby similar ball` ,bearingsll theouter races of which are receivedglietween nuts 63 and rings 64. l

Asi` shown in' Figure .11B\I ring 64 isnengaged hyena annular sealt housing 65 which contains ring; 66f'of Vresilient -A spring washer 69 engages ring 67 which compresses seal ring 66 against housing 65 and a sleeve 7l) and also urges housing 65 against ring 64. Carbon ring 71 is pressed into sleeve 70. Spring washer 69 urges assembly of sleeve 70 and ring 71 against a lapped surface 1 on.ring 73 which is pressed on both ends of. shafts 60 and 61. The seal assemblies are indicated in Fig. l by numeral 75 and these seals operate to resist leakage of .liquid to the left of the sleeves 50i and 51jc and to the right of the sleeves 501' and 511'. These seal assemblies are purchased parts.

Referringto Figs. l and l1, shafts 60 and 61 provide meshing, helical gears 80 and 81, respectively, which, as shown in Figs. and l1, rotate, respectively, clockwise and counterclockwise. vThe end thrust produced by the helical gears on the shafts 60 and 61 is taken up by the bearings 62. The gears S0 and 81v are enclosed by arcuate layers 82 of babbitt bonded to housing 32 and also by layers 83 of babbitt bonded to cylindrical plates 311 and 31r (Fig. 1). .The right end faces of gears 80 and 81 are held closely with respect to the babbitt layer 83 of plate 31r with a small clearance determined by adjustment of left nuts 63. The babbitt layer 83 of plate 31j is held closely with respect to the left end faces of gears 80 and 81 with a small clearance determined by the ad justment of nuts 63 (Fig. 2). Thus the gears 80 and 81 fit closely between layers 83. A function of the layers 83 is to pick up small particles of foreign matter which had passed the 40 micron tilter and which became embedded in these layers.

The liquid enters the pump through screen 42 and thence through duct 84 (Fig. 2). The rotating gear teeth pick up this uid and force it through outlet duct 85 and screen 40.

A mounting member 100 which is shown diagramvmatically in cross section in Fig. 25 provides an annular pump receiving recess which includes chambers 101 and 102 surrounding the screens 42 and 40, respectively; and these chambers are separated byv a gear housing flange 103 which is sealed with respect to the member 100 by a seal ring 104 received by an annular groove 86 (Fig. 1) of the gear housing. Chamber 101 receives liquid under relatively low pressure which flows through a duct 105 from the outlet of a booster pump; and chamber 102 discharges liquid `under relatively high pressure through a duct 106. l

Referring to Figs. 19-24, sleevesy 50r (Fig. 19) and 50jt (Fig. 2l) have, respectively, pressure luid receiving pockets Ar, Br, Cr and Dr and Af, Bf, Cf and Df, which are, respectively, equal in area and which are spaced by babbitt lined sealing segments I, II, III and IV. Sleeves -51r and 51f have, respectively, pressure fluid receiving `pockets Ar', Br', Cr', Dr' and Af', Bf', Cf', Df which are, respectively, equal in area and which are spaced by babbitt lined sealing segments I, II, III and IV,

Pocket Af of sleeve 50] (Fig. 2l) is connected by duct a1 with annular groove a2 of housing 30j (Fig. l). Annular groove a2 communicates with a notch aN (Figs. 8 and 4) in housing 30jc connected by a duct a3 (Fig. communicating with the pump inlet passage 84 (Figs. l10, 1l and l5) whereby the pocket Af is subjected to the pressure of the liquid entering the pump.

Pocket Bf of sleeve 50jc (Fig. 2l) is connected by duct b1 with annular groove b2 (Fig. l) of housing 30jc connected with duct b3 which appears in Figs.`4, 7, 10 and 1`1.

' 1 Pocket Cf of sleeve 50f (Fig.'2l) is connected by duct with annular groove c2-of housing 30jC (Fig. l) connected as shown in Fig. 5 with duct c3 Which appears in Figs. 4 and 10.

Pocket Df of sleeve 501c (Fig. 21) is connected by duct d1 with annular groove d2 (Fig. 1) of housing 30] which is connected, as shown in Fig. 4, by duct d3 with pump outlet duct 85.

Pocket Ay" of sleeve 51jC (Fig. 23) is connected by duct a1 with annular groove a2 of housing 30f (Fig.l) which connects with notch aN (Figs. 8 and 4) connected by duct a3 with pump inlet duct 84, as shown in Figs. l0 and l1.

Pocket Bf of sleeve 51f (Fig. 23) is connected by duct b1 with an annular groove b2' of housing 30f (Fig. l) which, as shown in Fig. 7, is connected with duct b3', the end of which appears in Figs. 4, l0 and 1l.

Pocket Cf of sleeve Slf (Fig. 23) is connected by duct c1 with annular groove c2 of housing 30j (Fig. l) which is connected, as shown in Fig. 5, with duct c3 appearing in Figs. 4, 10` and 1l.

Pocket Df of sleeve 513c (Fig. 23) is connected by duct d1 with annular groove d2 of housing 30f (Fig. l) which is connected, as shown in Fig. 4, by duct d3 with pump outlet duct 85.

Pocket Ar of sleeve 50r (Fig. 19) is connected with annular groove a2 of housing 30r (Fig. l) which is connected, as shown in Fig. 9, by duct a3 of housing 30r with pump inlet S4.

Pocket Ar of sleeve 51r (Fig. 19) is connected with annular groove a2' of housing 30r (Fig. 9) connected by duct a3' with pump inlet 84.

Pocket Br of sleeve 501- (Fig. 19) is connected With annular groove b2 of housing 30r (Fig. l) which is connected, as shown in Fig. 7, with duct b3 of housing 30r which appears in Fig. 3.

Pocket Br of sleeve 51r is connected with groove b2' of housing 30r which is connected, as shown in Fig. 7, with duct b3 of housing 30r which appears in Fig. 3.

Pocket Cr of sleeve 50r (Fig. 19) is connected with annular groove c2 of housing 30r (Fig. l) whichis connected as shown in Fig. 5, with duct c3 of housing 30r which appears in Fig. 3.

Pocket Cr' of sleeve 51r is connected with groove c2 of housing 30r which is connected, as shown in Fig. 5, with duct c3 of housing 30r which appears in Fig. 3.

Pockets Dr and Dr of sleeves 50r and 51r, respectively, are connected, respectively, with annular grooves d2 and d2 of housing 30r connected, respectively, with ducts d3 of housing 30r which appears in Fig. 3. Duct d3 of housing 30r is connected with the pump outlet 85.

If, for example, ythe pump is used to increase liquid pressure from p. s. i. inlet pressure to 600 p. s. i. outlet pressure, the four A pockets receive liquid at 150 p. s. i. pressure and the four D pockets receive liquid at 600 p. s. i. pressure. The four C pockets receive liquid at pressure somewhat less than 600 p. s. i. and the four B pockets receive liquid at pressure between 150 p. s. i. and the pressure of the liquid at the C pockets. The locations of the pockets, the areas of the pockets and the unit liquid pressures at the pockets are such as substantially to balance out the forces to which the shafts are subjected by the gear tooth loading and the hydraulic loading of the pump. In other words, the bearings 62 of each shaft are subjected to the resultant of forces includingthose derived by gear tooth loading and hydraulic loading of ythe pump and to forces derived from the pressure pockets which surround the larger cylindrical portions of the shaft. The resultant of these forces is a force of relatively small magnitude applied radially of the shaft axis and varying in amount and in direction of force application. In the case of a gear pump constructed in accordance with the present invention to boost liquid pressure from 150 p. s. i. to 600 p. s. i., the value of this resultant is about 35 p. s. i. which the shaft bearings can withstand without appreciable wear for a long time.

Because side thrust of the shaft journals has been reduced to practically a negligible value, the shaft bearings can be relatively small in diameter in consequence of which the gear shafts can be relatively close together and a compact construction results.

While the embodiment of ythe present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. A gear pump for pressurizing a liquid comprising a gear housing having an inlet and an outlet, shaft bearings, parallel shafts supported by said shaft bearings and extending through the housing andv providing meshing gears in the housing and each shaft having two cylindrical portions located at opposite sides of the meshing gears and adjacent thereto, four sleeves, respectively, receiving the cylindrical portions and each sleeve having a plurality, more than two, of liquid receiving pockets which are defined by longitudinally extending grooves closed at their ends and` further closed by portions of the cylindrical portions of the shafts and spaced circummerentially by sealingtsegments on said sleeves having close clearance with said cylindrical portions, and means providing bearing supports and sleeve supports and` ducts which connect the pockets of each sleeve respectively with regions Aof the pump at which the liquid is at different pressures, the location of the pockets, `the areas of the pockets and the unit liquid pressure at the pockets being such as substantially to balance out the forces to which the shaft bearings are subjected by the gear tooth loading and the hydraulic loading of the pump.

2. A gear pump according to claim 1 in which each sleeve has four liquid receiving pockets which are connected, respectively, with the pump inlet, the pump` outlet and two dilerent regions of the pump between the inlet and outlet.

3. A gear pump for pressurizing a liquid and comprising shaft bearings, parallel shafts supported by said shaft bearings and providing meshing gears and each shaft having two cylindrical portions located on opposite sides of the gear, sleeves respectively receiving the cylinl drical portions, two housings each supporting two shaft bearings and two sleeves, a housing surrounding the gears and located `'between the sleeve housings, means for securing the three housings together, pump inlet and outlet passages provided by the gear housing, each sleeve having a plurality of liquid receiving pockets which are defined by longitudinally extending grooves closed at their ends andfurther closed by portions of the cylindrical portions and spaced circumferentially by sealing segments on said sleeves having close clearance with said cylindrical portions, and ducts provided by the Isleeve and the sleeve housings for connecting the pockets of each sleeve "respectively with regions of the pump at which the liquid is at different pressures.

4. A gear pump according to claim 3 in which the ducts associated with the pockets of each sleeve include spaced, internal annular grooves positioned in the sleeve 6 housing, holes provided by the sleeve for connecting its pockets respectively with the grooves of the sleeve housing and passages provided by the sleeve housing for connecting the grooves respectively with regions of the pump at which the liquid is at different pressures. l

5. A gear pump for pressurizing a liquid and comprising shaft bearings, parallel shafts supported by bearings and providing meshing gears and each shaft having two cylindrical portions located on opposite sides of the gear, sleeves respectively receiving the cylindrical portions, two housingseach supporting two shaft bearings and two sleeves, a housing surrounding the gears and located between the sleeve housings, two plates each of which is located between a sleeve housing and the gear housing, means for securing the two plates and the three housings together, the interior of the gear housing and the sides of the plates adjacent thereto being lined with a relatively soft metal in which particles of foreign matter Iin the pressurized liquid can become embedded.

6. A gear pump for pressurizing a liquid having a supporting member, a cylindrical member received by a cylindrical recess in the supporting member and forming an enclosure, said enclosure comprising a middle or gear housing having cylindrical flanges, cylindrical plates respectively abutting the cylindrical anges of the gear housing and cooperatingV therewith to enclose meshing gears, two end housings, each having cylindrical flanges, one flange of each end housing abutting a cylindrical plate, parallel shafts extending within the parts of the enclosure and providing meshing gears in the gear housing and between the plates, bearings supporting the shafts and supported by the end housings, pump inlet and outlet ducts provided by the adjacent anges of the end housings, said ducts communicating respectively with the spaces between the flanges of the end housings, and a seal provided by the enclosure for cooperation with a wall of said recess of the supporting member to block ow of liquid between the spaces between the ilanges of the end housings, the supporting member providing ducts communicating respectively with said spaces.

References Cited in the le of this patent v UNITED STATES PATENTS 1,021,180 Clifton Mar. 26, 1912 1,379,587 Fisher May 24, 1921 2,111,883 Burghauser Mar. 22, 1938 2,176,787 Burghauser Oct, 17, 1939 2,220,588 Thompson Nov. 5, 1940 2,221,412 Rose Nov. 12, 1940 2,319,374 Ungar May 18, 1943 2,395,824 Herman Mar. 5, 1946 2,479,077 McAlvay Aug. 16, 1949

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