US3077839A

US3077839A - Pump constructions

Info

Publication number: US3077839A
Application number: US65665A
Authority: US
Inventors: John T Gondek
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-10-28
Filing date: 1960-10-28
Publication date: 1963-02-19
Anticipated expiration: 1980-02-19

Description

Feb. 19, 1963 GONDEK 3,077,839

PUMP CONSTRUCTIQNS Filed Oct. 28, 1960 IN VENTOR Job/7 Z om/e/r ATTORNEY United States Patent 3,077,839 PUMP CONSTRUCTIONS John T.-Gondek, 2206 Roosevelt St. NE, Minneapolis, Minn. Filed Oct. 28, 1960, Ser. No. 65,665 1 Claim. (Cl. 103-126) This invention relates to an improvement in pump constructions and deals particularly with a gear type pump having certain advantages over the conventional type of gear pump.

Gear pumps are conventionally made with an intermediate section including intersecting arcuate chambers to accommodate the gears, and end plates secured to the ends of the intermediate section to form the chamber ends. In some instances, pumps of this type have been formed with one end plate integral with the intermediate section. It is an object of the present invention to provide a pump having two generally similar sections each of which are provided with a cavity forming a part of the pump chamber. In other words, the central section is divided intermediate its ends, and the end sections are integral with the two center sections.

A feature of this construction lies in the fact that by having two similar pump sections which meet along a common line, the tendency for the pump body to deflect outwardly in a radial direction is very materially reduced. When high pressures are being developed by the gear pump, there is a tendency for the pump body to deflect in a manner to increase the bore size. As the body is not integrally connected to the end plates, this force is resisted by the strength of the body and the mechanical connecting means securing the end plates to the body. By dividing the pump housing intermediate the ends of the gears, the force is resisted by the integral end walls as well as the body, thus holding the body from radial deflection.

A further feature of the present invention lies in the provision of a means of relieving the pressure between the gears at a point of dead center between the two gears. In a gear pump, the teeth of the two gears do not ordinarily mesh perfectly so that there is normally a certain amount of oil which is trapped between the teeth intermediate the axes of the two gears. This point is between the inlet and the outlet of the pump. The oil which is trapped between the two gears at the point of dead center must escape either between the teeth or past the ends of the gears or between the gears and the end walls of the pump housing. This creates a frictional force between the gears which tends to increase the power required to operate the pump. I have found that by relieving the pressure between the gear teeth at the point of dead center between the gears, two important results may be achieved. In the first place, the frictional force caused by the trapped liquid may be eliminated. In the second place, if the trapped liquid is directed toward the axes of the gears, this liquid may serve as a lubricant for the gear shafts. This is particularly advantageous when the pump is idling at high speeds and has no head pressure to work against,

To this end, I have provided slight chamfers in the gear housing encircling the gear shafts and extending into the end walls of the housing. A small groove is provided on a plane through the axes of the gears connecting the two chamfers. This groove is in communication with the space between the gear teeth at their point of dead center permitting the pressure to escape into the chamfers, thus directing lubricant to these chamfer areas encircling the gear shafts.

A feature of this construction lies in the fact that the pump gears form a lubricating pump for the pump 3,077,830 Patented Feb. 19, 1963 minute groove in the end walls to the chamfers, from which it may pass along the journals to lubricate the journals. This has resulted in an increase in the rating of the pumps very materially. Pumps of the same size which were previously rated at 2,000 pounds per square inch are now rated at 5,000 pounds per square inch, and have been tested successfully at much higher pressures, due to the slight change in construction.

These .and other objects and novel features of the present invention will be more clearly and fully set forth in the following specification and claim.

In the drawings forming a part of the specification:

FIGURE 1 is a sectional view through a typical form of gear pump embodying the present invention.

FIGURE 2 is a sectional view at right angles to that of FIGURE 1, the position of the section being indicated by the line 22 of FIGURE 1.

FIGURE 3 is a transverse sectional view through the pump illustrated in FIGURES l and 2, the position of the section being indicated by the line 33 of FIG- URE 2.

FIGURE 4 is an enlarged view showing a portion of the gear teeth and showing the manner in which fluid is trapped between the teeth of the gear.

FIGURE 5 is an enlarged sectional view showing a portion of the gear housing .and the rotors supported therein.

The pump is indicated in general by the letter A. The pump includes a housing which is indicated in general by the numeral 10 and which includes a housing section 11 and a housing section 12. The

housing sections

11 and 12 are in abutting relation along a plane 13 which, in preferred form, is intermediate the ends of the gear chambers.

As is indicated in FIGURE 3 of the drawings, the

pump housing sections

11 and 12 are provided with

arcuate cavities

14 and 15 which are in intersecting relation and which are designed to accommodate the

gears

16 and 17 which comprise the pump, As indicated in FIGURE 2 of the drawings, the gear 16 is provided with stub shafts 19 and 20 which are supported in suitable bearings 21 and 22 in the

gear pump sections

11 and 12. The gear 17 is likewise supported with axial stub shafts 23 and 24 which are supported in bearings 25 and 26 in the

housing sections

11 and 12. The stub shaft 23 projects from the housing portion 11 and is preferably encircledby an anti-friction bearing 27, as the shaft 23 acts as the drive shaft for the pump.

As is also indicated in FIGURE 3 of the drawings, the pump section 11 is provided with

lateral passages

30 and 31 which form the pump inlet and the pump outlet. These

passages

30 and 31 are connected with inlet and

outlet openings

32 and 33 respectively which extend in a direction axially through the pump sections. These

passages

33 and 32 also extend through a pump base section 34 to communicate with inlet and outlet sockets 35 and 36 respectively.

A series of angularly spaced bolts 37 extend through the

pump housing sections

11 and 12 .and are threaded into the base section 34 to attach the sections together. It will be noted that the chambers for containing the

gears

16 and 17 exend to either side of the center line connecting the two pump sections so as to minimize the tendency for the extremely high pressure to deflect the body in a radial direction, or in a manner to increase the bore diameter. Radial deflection is prevented by the As indicated in FIGURE 4 of the drawings, there is normally a tendency for liquid' to be trapped in the space '40 between 'the'too'th'4l of '6ne"'gear such as 16 and the base between the teethas indicated at 42 in the other gear 17. As the gears rotate, this fluid under pressure must es'cape'either'between'the teeth'or about the ends of the gears. The compression of this fluid causes a tendencyto stop rotation of the gears, and requires greater pressure in "orderto keep them in operation.

As is indicated in the drawings, each of the pump housing sectionsll and 12 are provided with cham feis between the ends of pump housing and the ends of the gears 167 A chamfer'43 encircles the stub shaft19 in the housing section'll at'the end of the gear 17, and a similar chamfer 44 is provided in the housing section 12 at the opposite end of the gear 16. In a similar manner, charnfers 45'and'46a1e provided in the'housing setions'll and'12 at opposite ends of the gear 17. These chamfers extend about the journals 21'and 22 at their juncture with the 'gearreceiving recesses'14 and about the journals 25 and 26 atth'eir juncture with the puinp chambers 15. The ch'a'rnfers are very'small and terminate well short of the basesof the gear'teeths'othat there is no communication between the small chambers defined by the chamfers and'the exterior ofthe gear teeth except atthe point of dead 'center'between the gears. 'As indicated in FIGURES of the drawings, and as indicated in dotted'o'utline in FIGURE3 of the'drawings, a narrow slot or passage 47 is provided connecting the chzimfers43 'and 45 at 'one end of the gears'16 and 17 and conn'ectingthe chamfeis '44 and 46 at the opposite end of these-gears. This passage 47 is substantially narrower'th'an thewid'th of'the gear teeth'and is betwee -bur not connected with the inlet and outlet '

passages

30 and 31. The purpose of this groove 47 at each vend of the gears is toQpe'rinit' the escape of flu'idtrap'ped between the teeth astheteethpass through dead center positionbe'tween the 'ax'es ofthe 'gears. Thus "inplace of 'building'upa'highpressure inthe chamber 40 between the teeth of one gear and the base of the teeth of the opposite gear, rhirpressure is permitted to escape through the .groove 47 for use in lubricating thebearings of thegears.

Asan actual example, in ahigh'pressure punip having a"p'urnp bore ofperhaps fivefsixte'ehths of an inch, the

c'hamfer may "be abouffive 'to ten thousandths "of "an inch, and the groove or passage connecting these cham- 'fe'rs'rnay be of about equal 'width. 'At the hignpressu'res involved, this size is sufficient to properly lubricate the journals.

In accordance with the patent statutes, I have described the principles of construction and operation of my improvement in pump constructions; and 'while I have endeavored to set forth the best embodiment thereof, I desire to have it understood that changes may be made within the scope of the following claim without departing from the spirit of my invention.

I claim:

A gear pump including,

a pair of intermeshing'gears,

parallel shafts supporting said gears,

a pump housingcompr'is'ing a'pair of sections ofsubstantially thesanie crosssection throughout their axial lengths,

each "section including a 'pair of similar relatively shallow intersecting cylindrical cavities in a surface thereof, thecavities'mating to provide a gear chamber,

said sections including axial bores extending therethrough in concentric relation tosaid cavities to accommodate saidshafts,

the juncture betweensaid boies and said cavities being chamfered, and in which each section includes a groove connectingsaid'chamfers at the point of tangency of said gears, .and

boltsarranged in angularly spaced relation about said cavities securing said sections together.

References Cited in the tile of this patent UNITED STATES PATENTS 1,433,733 Lindsay Oct. 31, 1922 2,460,278 Cook Feb. 1,1949 2,624,287 Ilyin June 6, 1953 2,642,808 Thomas .June23, 1953 2,816,511 Korkowski et al Dec. 17, 1957 FOREIGN PATENTS 353}8l1 Germany May 27, 1922 417,316 Italy Jan. 14, 1947